Invisible Inc is turn based stealth, from what I've seen, but doesn't follow XCOM rules. Also, having to move in turn-based mode to extraction is excruciatingly annoying, as it just wastes your time for no reason (mainly when there are no threats and you just have to move all your units one by one, step by step to the extraction point). Also, there were points I didn't know what I was doing, but it seemed to work.
In Phantom Doctrine, the complexity therein is messy, and it feels like they just took XCOM and added a new coat of paint (some stuff doesn't make sense). XCOM is much more fun in a pulpy sort of way, and the complexity makes sense. If you do go for XCOM, opt for Enemy Within instead of Enemy Unknown when playing. Found XCOM to be much more satisfying than Phantom Doctrine.
