I delivered at Mission in June 2007. I had a pretty good experience, no interventions during labor/delivery that I didn't want. They were a bit pushy about the hep-lock, but I agreed to it because I had vomited multiple times while in transition. I was in one of the "water world" rooms, but didn't end up using the tub, because my labor was so intense that I didn't think of it.
I'm pretty sure they're fine with water birth, because my MWs had some pics in their office of a water birth that they did at Mission.
All women transfer after they have their baby from an L & D room to the mother-baby unit. The rooms are nice, but you do have to specifically request a water world room to get the deep tub to labor/deliver in. There are only 4 water world tub rooms, but not many people request them, so hopefully you wouldn't have a problem getting one.
I have to say my biggest complaint about Mission is there (lack of) nursing staff and LCs. I needed big-time help to get BFing started and I didn't get it. I had to come back for an out-patient appt. with an LC the day after I discharged from Mission to get additional help with BFing.
As for additional stuff and interventions for the baby: we allowed eye drops and Vit. K shot, but declined Hep B. It was surprisingly easy and no one gave us a hard time.
Let me know if you have any more questions about Mission!
Just out of curiosity, who is your MW?