I have often recommended Casta Diva as one of the good BYOB's in Philly. We had dinner there this past weekend, and this is our problem with it: the noise level was impossible.
The food was fine. They have their own version of Caesar salad, which was a very good salad though not typical Caesar. (I love the traditional one at Tre Scalini.) Our pastas and main courses were as good as ever. The menu is limited, but enough. No problem with service.
But when we go out for dinner on a weekend evening, we are usually with friends. It is our time to get together with people and talk. All of us had a headache from trying to communicate with each other at Casta Diva. It is small, and very noisy.
Also, the people sitting near the door were getting a cold blast every time someone came in. It wasn't too cold this past weekend, but I could see a problem in future months.
Some people don't mind a high noise level. And if it were just the two of us, it might have been okay; we talk enough at home. As it was, we won't be returning.