I went on the all girls birthright trip 2 years ago. I had a very mixed crowd, a lot of lubavitch girls, some bais yaakov girls from brooklyn, and some YU kind of girls. I just met someone a few days ago who went this past winter and she had a basically all bais yaakov type of group and the madrichas were also bais yaakov. She had a fantastic time! It depends on your group and what kind of personality you have if you’ll enjoy it. We did have an option to a go to a bar one night, and whoever was interested went. Trips were really good and extending your ticket is really cheap so I stayed an extra week. The hechsher was good, we ate very nicely. They serve 2 meals a day so the third one they drop you off on teh steet to find a good restaurant.
It was totally worth it, we went on great trips and everything was free and i extended my trip for a 100 bux or something like that. Great experience! Go with friends though if your quiet type. And no you can’t leave the group EVER but there was time for people to visit you on Motzai shabbos. Go with friends and you’ll love it!