Just one, because I played S.E.4x solitaire. It was a Doomsday Machine game, so it didn’t really capture the great feel of the game, but I hadn’t played in a year and wanted to re-learn the rules. I posted a mini session report on BGG.
I also (finally) read the expansion rules. Well, the first expansion. It seems like … a lot of chrome. And a lot of paperwork. My quick thoughts (all of which are based on not playing it) is that most of it adds too much paperwork for the goal, but if you really loved the system and wanted to make SE4x a lifestyle game, you’d ease into it fairly well. Still — each thing added slows the game down. Although some of them seem like good ideas (assuming they are balanced).
In particular, giving each player a special power (which can be revealed at the appropriate moment) is highly thematic. Oh … player X is a warrior race and can attack twice in the first round of combat, but can’t retreat for a while (and suffers penalties in the second round). Player Y can ignore maintenance costs (and doesn’t have to reveal the card, ever, except at the end game). Player Z reveals at the start, but gets a bunch of free colony ships and colonies and explorations before the game. That, and conquering alien planets for unique technologies … yeah, I’d throw those in. (Also pre-game rolls to randomly adjust some universe conditions). But ground combat (and troops), individual ship ratings, design your own ships (prior to start of game, not during!), flagships, etc? I’m not so sure. I should probably try to get a group to play this again, but it’s a nice change of pace from Mage Knight for solitaire….
Update — I tested out some variant rules for the AP scenario.