I tried the United Empire on my usual four-arm galaxy just to get a feel for how things have changed.

The Good

Combat is much better.  I have a real sense that I'm building for a strategy, especially since I need to choose my military technologies more carefully. Militaristic gameplay seems more interesting to me now.  As an example, I found myself fighting technologist pirates exclusively, who focus on energy and shields, which is now (thanks to the new system) obvious to me, so I focused on energy defense and projectile offense, and would usually walk away from what the computer predicted as close fights with total victories.  I'm also able to analyze the results of the battle, or see what I need to adjust to deal with an enemy.

Politics also seems better.  I'm more readily able to increase the number of laws I have, I'm better able to see how my actions directly impact my politics, and I feel like i have more laws to choose from.  I don't really see or understand what "political experience" represents, though.  I don't think I've unlocked any laws, and I don't know where to go to see how close I am to unlocking laws.

Strategic resources are much more useful.  I could not find any titanium anywhere, and man, did I feel that pinch.  In update 2, I wouldn't have noticed.

Dealing with minor races is much more satisfactory this time around.  Working at making them happy or going to war provides to interesting benefits, and I think not assimilating races might prove as valid a tactic as assimilating them, depending on how you want to deal with them, though of course, I think unassimilated races spawn pirates. Hmm.

I got further in the Sheredyn questline than ever before!  The need to have 3 militaristic laws is much more reasonable in this version (and I can see the story that it's telling more clearly)

The Bad

I thought the marketplace fluctuations were interesting, but I couldn't interact with them, because I couldn't sell anything. The whole screen is shifted slightly to the left, which seems to be covering up the sell widgets.  So, Jadonyx prices skyrocketed, I had tons of Jadonyx, I should have made a killing, but couldn't.

I have less pirates to deal with, but worse pirates.  They spawn cruisers pretty quickly, and that can be effectively unbeatable in early game.  They're not a serious problem one I had a serious handle on things militarily.

The Riftborn.  Wow the Riftborn.  They might be overpowered.  I say "might be" because I don't know what their starting position looked like, but I know what mine did.  I had, in my entire constellation, three planets I could colonize, and I was 16 turns away from the next constellation by standard travel.  I was really tucked into a corner.  I also had access to very few resources and quite some trouble with pirates early on.  By the time I met the Riftborn, they had taken the galactic center, their galactic arm, and part of the constellation between us.  They declared war on me and then proceeded to bear down on me with a giant, 11-ship fleet (4 + 3 + 3 + a hero), which means they were militarily tier 4, while the best I had managed was tier 3 and I was aggressively pursuing militaristic options. Wow.  Thus, even with several fleets of battleships and corvettes, I was unable to make a serious dent in their single fleet.  I had about 500 points, while the Sophons also had about 500 points, and the Riftborn had about 900.  They also seemed to have a really strong start, as they claimed several early competitions, including the first to colonize, what is it, 10 systems?

Now, I'm not a bad player (I almost always win on Normal) and I was playing Normal, just to get a feel for the game.  Granted, some things have changed, and my start was rough, so it's possible it's just the luck of the draw.  Endless games tend to snowball.  But given that the Riftborn excel at industry, which can facilitate everything else in the game, and they evidently have superior dust and science generation as well, and they can gain extra turns, I wonder.  They had nearly twice as many points as the next AI I met, which suggests that in a straight AI-vs-AI fight, the Riftborn would win.  That suggests that something might be benefiting them.  That's either a really good start compared to really bad starts by other empires (it happens!) or an undue advantage for the Riftborn.  It's also a single datapoint, but I thought it might still be a useful data points.

The Ugly

I've seen several instances where words get mashed together, including the marketplace screen.  My last resource, the green lightning, is out of the resource box and just below it, to the left, as though it has been pushed out it's "line" and performed a "return carriage" back to the left.

Ground combat is a little unclear.  I had 140 troops vs 100 manpower on a world I was invading, but that translated into like 20 opposing troops and a battle I thought would be close turned out to be a cake walk.  It's less clear now how to work out my odds of a ground-battle victory.