ME2 is certainly not tactical. It throws you right into the action, very much like Gears of War.
There is some tactics involved, the problem is on Insanity the combat almost requires you to have a team of people with Biotic/Tech powers. Before you could get by with Soldier techs quite easily but on Insanity absolutely everything has a Shield or Armour which renders most soldier techs useless.
Some fights just weren't really balanced for it. The 'ambush' on the ship is just ridiculous and took me so many retries before i could do it without simply getting overwhelmed, not by a fault in my own tactics (not theres any space for it) but because the miniboss can just waltz straight upto you and knock you out of cover. Even better when he takes over a very nearly dead collector and suddenly you're fighting something at full health plus again.
I won't deny that in places, Insanity makes fights simply epic. Such as the Colossus fight (though without the nuke launcher killing the colossus itself would've taken forever), but Collectors in particular it just sucks for.