Sooo, I picked up ME2 in the Steam sale and just finished it. Damn but the Krogan-grade shotgun is awesome. I AoE Charged into everything, one-shotted anything that was still standing, and in the rare cases where something survived that, FISTO. Who cares if it fires once before reloading? One shot is all you need. Once I got [spoiler]Garrus[/spoiler]' AP ammo I only had to pull out the heavy pistol to deal with Scions.
I liked how the plot is structured like a caper movie: you put together a team, then you commit the elaborate heist. It's kind of a shame there wasn't really any story progression though, no uncovered mysteries to speak of, apart from finding the enemy's location. I did have that ohhhhh shiiiiit moment when I saw the [spoiler]final boss[/spoiler] though, that was a cool moment.
Overall, yeah, it's a much better game than the original. Less running errands, more actual action in unique environments, and a chunkier, more focused leveling system. If ME3 is as improved over ME2 as the latter was improved over ME1, we're in for a treat.