The bulk of my commendations have actually come during 3.2, where I would endlessly queue up for Wiping Cities and save bad groups from dying as an AST. I find that in random faceroll content like expert, I get a fraction of the amount, simply because so little is really required of me (or anyone, for that matter).

My gist is, you'll stand out more performing well in content where people don't generally already perform adequately. I used to get a lot of comms doing well in Titan HM when i110 gear was the cap, as well (so back when DF pugs still struggled with it). Meanwhile, my co-healer in Syrcus Tower could be 100% afk and my teammates wouldn't notice a thing, and I'd get no comms. Of course, this is my healer-only perspective, so it's not like this advice is blanket technique for everyone.