I do not want to dismiss this new Endless Legend styled technology/science system out of hand, but I do enjoy a good tech tree, so here are a few of my suggestions.

First, I appreciate the idea of an era system that delineates and checks technological advancement in game, but for reasons similar to those expressed clearly by Fenrakk101 and others I feel that it is overall detrimental to both gameplay and aesthetic appeal, as well as unfaithful to realistic scientific method and the theme or plot of Endless Space II.

The era system in itself I think I could get behind. While it is not a necessity, it effectively acts as an additional prerequisite system by requiring not only specific research paths, but also a more general spread; however, in my opinion it would make more sense to adjust its implications to effect branches of the individual tech trees differently.

Here one of many ways that eras could be used while hopefully avoiding the concerns are being mentioned:

If achieving a specific era two military technology required a standard chain of prerequisites in the era one military branch along with a certain number of research points in applied sciences (certain techs would be worth a set value of research points based on how deep into their tech tree they are). Unlocking the military era two would not unlock the the second era in applied sciences, diplomacy and trade, or exploration and expansion tech trees.

This would fill the role of requiring some early investment into at least two separate branches, even when dedicating an empire to one game plan, without restricting freedom to expand into other areas later in the game if necessary.

Additionally, it is a better representation of how technology actually develops, being close to, yet more sophisticated than, the Endless Space tech tree. A player who neglected to fortify his or her empire early on could go back for those techs without massive penalties aside from simply being behind more aggressive opponents, but would not be able to simply skip lesser value warfare improvements, giving an unfair advantage to those who ignore their military at first and then, when the cravers come around, use their science advantage to possess better combat technology before a significant number of their systems are compromised.

It is natural for the techs to be much easier to know once more resources are available to be dedicated to learning because the tech remains comparatively simple (one that was quick to research even when hardly any resources where available).

In chemistry, similar concepts are presented in some equations (when the temperature of a gas [information of a tech] is constant, the product of its pressure [time required] and its volume [science per turn] will always be the exact same value because as volume increases pressure decreases).

Endless Space is largely a struggle of momentum. Whereas in a comparatively fleeting war like those on Earth one leap in technology of advantage in military might (think world superpowers) can have a massive impact and then fall off as enemies adapt (what country doesn't have machine guns now), in a war of the sheer magnitude of Endless Space, one empire may develop only its military might and expend the rest of its resources on implementing what it has learned, another might developed its economy. When the militarists show up it will be crushed, but if they are occupied elsewhere for a while there will be time to catch up and diversify.

This not to say that a defined time segment exists in which one strategy is better than the other. The scientists may expend heavily into warfare to try and know more warfare tech than the militarist faction, but because they are naturally less adept in that area it will essentially restrict their progress in other areas that might give them a later advantage in order to match their enemy who is doing what they want to be doing. Fighting still works late game because long term development yields massive fleets with great firepower. The scientists may become so far ahead in technology that they can do many things, while the warlike races are best at fighting, but if the scientists determine to spread themselves out in this way they cannot match the militarists at this aspect of the game, because the militarists are more invested in it.

In regards to price scaling, increasing the costs of all technologies based on how many technologies are already discovered makes no sense to me. Typically knowing one thing makes it easier to know other related things, which is why tech trees are realistic and also why schooling is separated into categories (mathematics, various sciences, language arts, skills training, etc cetera) that progress through generally stable curriculums (basic arithmetic, fractions and decimals, algebra, geometrics, calculus) in an order that builds upon previous knowledge.

Sometimes scientific leaps do occur (for example the invention of superglue), but they never happen spontaneously (in this case an attempt was made to develop a new plastic for use in cockpits using similar base knowledge to that required to invent superglue). This is represented by a tech tree similar to that of Endless Space, in which the trees folded in on themselves, allowing most researches to be approachable by two paths of development.

I do not see a problem with technologies having variable research costs based on certain factors, but I do not believe that the number of previously developed technologies should be one of those factors. Decreasing prices based on other known technologies was used sparingly in Endless Space, and making these sorts of connections more common would definitely improve scientific gameplay.

Along these lines, I do like the increased interaction of technologies that is planned (the new "links" as explained in GDD 7). These could include reducing or inflating prices, providing bonuses when both are unlocked, and allowing research of only one of them.

My opinion is that a technology progression (but not the available options) should be be able to be linear, with certain values that can be steadily improved (like the blue and green fleet speeds in Endless Space), and other static unlocks (such as "you may now forge alliances" and "you may now travel via wormholes").

Random, inconsequential technologies may cluster the tree and take away space that could be invested in more impactful innovations, as well as antagonize people who know that certain parts of their path will ultimately be useless.

Endless Space did a pretty good job of this and was very fulfilling in these ways.

Currently, the most obvious issue to me is implementing a justifiable scientific victory condition. Using the old route, if no tree has to be progressed on then anyone can start on the victory tech once they are in the right era. To account for this the tech must be a massive (ridiculous) investment, and since nothing is gained from it in the meantime, science begins to fall behind elsewhere. This could be solved by having bonuses provided as it is progressed on, but then it is just a separate tech tree, and if no branches are provided a pathetic one at that. None of these options are conducive to an engaging experience.

Another major drawback is that while through the era system you are provided immediate access to a wider selection of researches, you have less freedom in what you want to not have in favor of your choices. Additionally, consider the following: while if the first era contains say five military technologies, but those five are packed into the bottom two tiers of a tech tree (with two and three tech options respectively), and you wanted a tier two tech, it could be the first research with eras and have to be the second with a tree; however, if you wanted a tier three tech the era system would still require ten prior completed researches and the tree would only take two. I do not think that with the current iteration of the era system the comparative techs are quite so dense, but even then, in order to not have a massive number of technologies available in each era, fewer total technologies exist, which decreases player options even further.

Personally, I do believe that the era system can be made much better than it is, but only by incorporating formatting distinctions inherent to tech trees at a massive degree.

Surely there are aspects of these suggestions and evaluations that I have overlooked. Please come up with more and post them.

Basically, I do believe that the tech tree should be developed and improved, not just set aside while other areas that were lacking in the original Endless Space, such as diplomacy, are reworked. I trust that the current system can be evolved into one that is more entertaining to work with. Make science glorious again.