I've finally TRed and am playing heroics again, one and done all quests on elite. My reaction to the current champion implementation is: meh. It's fine. I don't really notice them. I suppose the lower heroics are marginally more difficult, but not enough to mean much.

The only noticeable part is when there's a champion archer who can't be easily reached, like on the perches up high in Swiped Signet where you have to run all the way around the ramp to get to them, and if you try to do so carelessly the wizard standing by them will blind you and catch you in a sleet storm. hehheh. Two of those archers were champs in my run, so I found myself stopping to thrower them to death before resuming the faceroll.