Hi, my best friend and I go every time we are at Disney. We love it. It is alot of fun and by the time you leave--you may not have a voice from all the singing and shouting (all optional-of course).
We usually go around 9:30 to get a good table, and to make sure to get a table. If you go during the week, probably will not have a problem getting a table. If you go on the weekend, I would go early.
It is one of the last places adults can go after hours on property, since they closed down Pleasure Island. If you are going to drink, plan to take a cab back to the hotel, unless you are close by and can walk back to your room. The cabs are at the BW main lobby and are easy to get and an inexpensive and safe way to get home.
Hope you go -- have a great time.