I had been looking forward to the Proving Grounds, since I do like to challenges.
I did, however, expect somewhat more of a challenge for the Bronze, Silver and Gold trials. You are, after all, "proving" yourself. Maybe I was expecting the difficulty of Challenge Mode Dungeons, I don't know.
In any case, I breezed through the Gold DPS. I'm confident of doing fairly well in Endless, but I'll need to be more awake when I start it, not after a raid!
...and just because I'm me, I attempted the Bronze Heal and Tank mode. Sadly, pet tanking is seriously lacking, otherwise I'd definitely want to give it a go. I suppose this is one of those times that I'll have to make use of my druid. I only hope he's geared enough!