Well, I decided to play ME2 for a bit instead of writing this week but here are my thoughts.
Gameplay-wise, massive improvement. I did not miss the clunky inventory interface as well as the piles of guns you sold every time you went to the shop. I did miss the upgrade system with guns but it's mostly replaced with ammo powers and a simpler upgrade system. The gunplay feels much better and thermal clips force you to switch between guns when/if they run low.
Story-wise, it's quite an improvement. Plot-wise however, it feels more clunky but that's due to the mission structure which really annoys me. It streamlines things and puts it all together, but at the cost of being able to do whatever the hell you wanted. Furthermore, plot progression really hampers things. You get an optional character to recruit near the end of the game but due to the way the progression is set up, you can only get one mission done with him without negative plot consequences.
Love the conversations as well as the Paragon/Renegade interrupt that should have been in the first game.
Altogether, a great improvement but it has its disappointing moments from streamlining.