First time I'm chiming in on the 4.0 onwards stuff, and it is fantastic. I was skeptical when I grabbed an early release of the unity version, but the finished product is amazing. 4.x feels like a new game, and this looks like it's continuing in LotS, which I bought as soon as I saw it. Waiting until there is a little more of the story stuff in and somewhat balanced before doing any campaigns with LotS, as I want my first discovery of the new features to be as full and enjoyable as possible. Looks outstanding though.
One little frustration I have had with my most recent failed campaign, is forcefields occasionally selecting with military ships when a box is dragged round them. I realise this may be a feature not a bug, so that things like MRS etc can be grouped with the fleet more easily, but for forcefields it seems more dangerous than useful. In a frantic (and ultimately doomed) attempt to deal with a CPA, I dragged a box round all my military ships on a planet and told them to move somewhere. Unfortunately this also moved my FF that was over my CS and two power gens. The AI hit them before I could correct for this, killing the planet, and through the sudden loss of 120,000 energy production, defences on my other worlds. Things did not progress well from there.
Just a little niggle though, the rest is just dandy. Keep up the good work!