Cielos are decent to steal. You don't get designate target, but their buff isn't bad at all, shield regen and damage bonus. Overseers have their hp injection also. Only having a few of these won't really make any big noticeable difference, but if you manage to steal enough they'd be a good enough addition. The Cielos can throw their buff on a good number of ships, and Overseers just add 250 hp with their ability, so a couple of them do a good job at keeping a capital up that's being focus fired.

does it work on Cap ships?

if it does, i would have thought that the answer is obvious?

i must say though, its most likely better to steal ships with unique abilities, support cruisers and the like, that way you get buffs that could complement your fleet very well, and will have an advantage over someone without the same abilities

This would be an interesting test!!! Capture an Advent or TEC constructor and try and make a starbase.  I don't think it would work for Vasari since colonizers are granted the ability via a tech, but since Advent and TEC use a tech to make a constructor ship with a default ability, it seems like it might work in theory.

Even if it let you snag the constructor and build the base, you'd presumably be limited in module selection because you wouldn't be able to research the corresponding techs.

Stealing caps would be insanely overpowered, of course.  But note that dominating something like a Subverter is still slightly better than an instant kill; even though you can't use any research-dependent abilities (unless it's another Advent ship, presumably), you still prevent the enemy from using that ship against you, and it's one more target.

Yep, there is no advantage to having a baseline starbase with only default upgrades, but it would still be cool just to see if it was possible!

i dont know about host

i mean its for me this hapeens late game with my supply pretty much used up so if i steal things i wanna keep i have to schuttle for room and mess with my fleet comp

heavy crusers are good if im using them temporaily but again i need empty suppy for base constructors

but anyways overseers and cielos are good? then ill go for those

oh and the robo crusiers work if you steal them tho dont seem to really want to auto-cast repairs

This ability is not that powerful compared to sucking a planet dry or missile barrage but you can make a great combo : use the domination of the rapture combined the ability to reduce cooldown of the revelation battlecruiser.

By using that little trick, you can capture almost 50% more ships and it makes a huge difference in a 5 minutes long battle.

In fact, every time i start a game, i wonder if i have to go for a mothership or a rapture (which also works great with a radiance) and everytime i pick up a mothership

Dominated ships lose any hull/shield/armor/AM/DPS upgrades that their original owner imbued them with, but your researched increases in hull/shield/armor/AM (and for stolen Advent ships, DPS) will apply instead.

Say you researched +15% to hull and +30% to shield and you stole a Hoshi with +30% to hull, +10% shield, and +3 to armor. The Hoshi basically has its 30% hull bonus replaced by your researched 15%, its 10% shield replaced with your 30%, and loses its armor bonus since you don't have any research into armor. It would also lose any laser upgrades it had from its original owner (since TEC Lasers are not the same as Advent Lasers and are not affected by the other's research).