It sure is memorable and then, feeble baby Reaper...But the Suicide Mission is one of the best final levels in video game history.
I think it did quite a few things right, but if I were forced to choose play on repeat either Suicide Mission or final Citadel run from ME1 (I'm walking destruction) I would probably choose the latter.
But it was great idea, quite memorable and were been even better if they made it a bit longer and dropped the feeble Reaper, replaced a scene where Shepard cuts power from proto Reaper chamber or whatever and have dialogue wheel scene with choices to destroy it or to give it to Cerberus.
Must say though that I don't remember for sure if I finished ME2 on Insanity or not, probably did. AI being what it is, levels being short and most importantly enemy count that doesn't appear to change, they just become bullet sponges, it loses it's charm on replays.
I liked how they were tactical decisions and how choices made earlier in game (like upgrading Normandy or not) had consequences. Yeah, there were some good ideas.