I saw By the Bog Of Cats this evening with A. I thought it was excellent. You had to buy into her crazy, tortured soul, but since she reminded me of several people I knew, it was a bit easier (I know so many crazy, tortured people!). Mild spoilers, so if you're seeing it before it ends its run on the 26th, stop reading now.
It could have been acted better. I think she's an excellent actress, but maintaining the accent took up too much of her energy -- if they'd dropped the accents and just had the same plot I think it might have been an equally good if not better play. Only the jokes relied on the accents and they're easily substituted.
They also could have made it clearer that she was mad. It's one thing to be a sympathetic villain, but her actions seemed less deranged, more stupid -- in particular, they didn't stress enough how much abandonment by her mother had unhinged her until far too late in the play.
On the other hand, she was really hot, so that's good :-) Although she did rather overdo the sultry stalking around in transparent gown; we get it, you're really sexy, now get on with the acting, dear. Only the waiter was at all interesting out of the rest of them.