I thought her anti-Vulcan remarks to Spock were funny (both because of how they were written and how Denise delivered them). I got a big laugh out of
"I *hate* Vulcans. I hate the logic, I hate the arrogance. VERY WELL!". I especially appreciated the way she nailed that
"very well", but in concept and execution, the character was just weak.
I wouldn't go as far as Brutal Strudal, but I do think the existence of this character tainted
"Yesterday's Enterprise" somewhat. I just cringe in that scene where Sela is explaining her existence to Picard. It's just such an unnecessary drag to learn that Yarr ultimately did have a rather meaningless death (killed by her forced husband due to her forced daughter ratting her out? wtf?

) after how beautifully
"Yesterday's Enterprise" undid the damage of
"Skin of Evil" by sending the character off in grand fashion.
There was no reason to see Denise Crosby again between
"Yesterday's Enteprise" and
"All Good Things...". I'd rather have her second death be a mystery (so we could dream that her and Castillo got together someday without knowing that's impossible) or have it implied that she died with the crew of the previous Enterprise to help establish the Klingon and Federation alliance.
At least
"All Good Things..." made sure Denise Crosby's last appearance on the show was more dignified than it would have been if we hadn't seen her again after Sela. First Sela comes in with a ridiculously laboured backstory only to be thwarted with a pathetic amount of ease by her enemies
twice. Not a very impressive character or character arc.