I finished Mass Effect a few days ago and have begun Mass Effect 2. For your reference, I play a female Shepard Infiltrator class.
– It’s a lot more action oriented. The “tell other companions what to do” bit is much more streamlined and less finicky. There are fewer skills to research (a pity) but that’s a minor complaint because the skills that do exist are pretty awesome.
– I’m still not really happy with the limited ammo aspect, but given that most classes seem to have some kind of combat skill, it’s not as bad as you might think. The heavy weapons are a nice touch — a huge upgrade from nigh-useless grenades in ME1.
– The carry-over from importing saves is both more and less substantial than I thought. It’s mostly story based, unlike Dragon Age to DA: Awakening, for example. The bonuses are nice, but not really ground-breaking.
– The loyalty mission aspect would be a lot better if there were truly mutually exclusive characters. I’m told it’s different if you’re male, but the loyalty system seems silly if you can make everybody loyal to you.
– No inventory management is a nice change.
Overall, I like it a lot. I’m glad that the Mako is gone; the resource mining is a little dull, but it’s certainly an interesting way to incite you to explore new planets. Credits seem harder to come by.