I got about 75% (lvl 30-ish, all but one ally's side quest resolved - I got lost in the assassin one) through it then remembered what you said about your ME1 save affecting events. I'd only given ME1 a cursory playthrough so figured I was missing a lot of cool stuff and stopped to start the first game again.
I just completed the game yesterday with a Lvl 27 Soldier. Yeah, after I finish
Dragon Age, I'm planning on re-playing
ME1 to see if I missed anything, and then give
ME2 another play to resolve some of the things I wasn't happy with this time 'round.
Pretty rad ending, although (as per usual) the final "boss" fight is somewhat bland. Getting there is incredible, though. You finally feel like you're using all of your squad mates.
I don't want to influence your decision-making too much, but I strongly recommend that you (a) complete all loyalty missions, and (b) invest in every upgrade possible. Now that I'm through, I'm reading over some of the other possible contingencies, and you wouldn't believe how much of a difference those two points will make. Some of them are literally a matter of life and death. You
do want to survive for
ME3, don't you?
Where did you get lost on Thane's mission?