Play it?

First time I went through as an infiltrator, no problems (besides a disturbing lack of sniper rifle...who the hell designed that loadout?).
If you pick an engineer or a "caster" class, then I noticed a huge, horrible change from ME1/2, which would be the cooldowns. I felt like playing an engineer was waiting behind cover for up to 30 seconds for the cooldown to expire and I just don't get it.

The gameplay has become more complex, more technical, and more tactical...and then they scale back skill use? It was very off-putting.