I've played enough to use pretty much all of the new stuff for each race, and here are my thoughts. Overall, Entrenchment is pretty good, but there are some things that need to be changed.
1. Starbases: The biggest, most exciting thing that Entrenchment added. Before the beta came out, they sounded really cool, but unfortunetly, they don't really live up to the hype. As others have mentioned, their range is pathetic, and they can easily be avoided. I like how you can build just about as many as you want, and that they can be built anywhere, but they aren't very useful. In uncolonizable areas, they are especially useless, except for the trade port part. With planets, you can at least build other defences to make up for the holes in the SB coverage, but at stars, wormholes, etc, you can't. Stars are perhaps the most worthless of places to build one. It can *maybe* cover one phase lane. The others are completly open. The Vasari one is nice because it can move, but it's so slow that it couldn't do anything about something at the other end of a star.
On the plus side, the SB's are pretty unique between the races. My favorite is the Vasari one because it can move, and it can act as a phase stabalizer. The Advent one is nice for all of the extra benefits it can give. It can add 30% alleigance to a planet. The TEC's self destruct is fun to mess around with, and can take out a decent sized fleet, although it can't finish off a capital ship.
Like others, I think that the range of SB's should be increased. At the very least, they should be able to cover half a gravity well, although the hole well would be better. It would also be nice if you could have more than one in a well. Maybe the size of the planet could determine the number of SB's you can have on it? Dead asteroids and asteroids can only have one, regular plants can have two, stars can have four, and everything else can have either one or two?
2. Mines: Mines are fun, and I like the different varieties (explosive, gravity, and homing) but something really needs to be done about them. Maybe a limit to how many can be in a gravity well? Or, the could be no limit, but scouts would need to be buffed. They should be able to reveal at least half the well, not just the tiny little bit that they do now. It would also be nice if they had some sort of mine sweeping ability. Give it a range of something like the current mine-reveal range.
3. Defence Tech Tree: Its a good idea, but it seems really lacking. There really needs to be more research in there. About half of the stuff is all SB upgrades. I'm not really sure what other stuff could be added, but there has to be some more defence related tech that could be put in there. It just seems empty.
Overall, Entrenchment is good, but it still needs a little work, and some balancing. I still give it
thumbs up, though.