Truthfully, now that we've seen her Britney (and I was a little underwhelmed, though I understand her desire not to make fun of a star who's her bread and butter), [...]

Yeah, I'd have wanted to see Derrick go into another kind of Britney. Not wanting to potentially offend Britney (there's no doubt in my mind that Britney or someone in her team is aware not only of Derrick but also of him being a participant in the show this year) was a bad move.

After all, Chad Michaels served up a hilarious Cher during her SG. And her impersonation wasn't offensive.

My best guess is that Derrick simply isn't funny when he's Britney?