I personally went with Pitbull.
Not really a whole lot of difference between Pitbull, Xperl or others.

I was looking for a party/raid frames addon, which would sort alphabetically.
Did not find what I was looking for, but found Pitbull to be the most attractive frames of those I looked at.

Ended up with Grid + Grid Custom Layouts and Clique for the click casting.
But so many people are singing the praises of Vuhdo, will definitely have to check that out.

I don't use a bars addon, although the wow default bars aren't very nice looking...
A patch basically cripples a UI, until the bar is updated.
My roommate uses Domino's and his UI looks very neat.
But alas, I have no experience with it for you.