Mass Effect on Insanity is tough fun.
Mass Effect 2 on Insanity is much less enjoyable.
The enemies take too many bullets to down which is a killer considering how ammo starved you are at the start of the game (e.g. primary weapon only holds 10 bullets). It'll get easier when I get my character some ammo+ upgrades plus a better weapon with a naturally higher clip capacity...but at the point that I'm at it's all frustration all the time.
Tearing down an enemy's Barrier, then Armor, only to have them survive multiple headshots with a sniper rifle is a wee bit aggravating in a game where the difficulty is as front-loaded as it is in this game.
Also, team AI is retarded. If you don't tell them to take cover they stand in the middle of an arena for a few seconds (losing their barrier in the process) and then slowly walk over to cover only to pop out of cover later and again stand in the middle of an arena. If you DO tell them to take cover, you still have to deal with their pitifully slow treck to their cover position.
These are things that were always present, just never as visible, on earlier difficulties.There where some low laying pipes in the Krogan homeworld that I wanted to climb over. When I touched them my character began to float up to the cieling. Save-->Load didn't fix it. Wish I saved before that happened because it was after an annoying fight with infinitely respawning Krogans.