Johnny,
I've had my PBT for almost a year. I got lucky and got him from a fellow reefer who was breaking his tank down. He was 5" when I got him and without getting out the ruler out I'd say he's put on at least an inch. He is a pig, I
feed blender mush(with alot of nori) and sheets of nori.
I drove up to Seatlle to get this fish and he spent almost 3 hours in a 5 gal bucket. Put him in my tank and all was well for the first couple of weeks. He got ich really bad for about two weeks and after feeding garlic soaked foods and adding a pair of cleaner shrimp to the tank the ich went away. I haven't done the garlic thing for awhile because the ich hasn't mad a comeback.
Every now and then he'll get a couple of white spots here and there but you have to look real hard to see them, I think my cleaners help out alot.
My tank is 6' and 18" front to back and it is HIS tank(don't tell that to my yellow tang though) keep in mind that. They posture alot at feeding time but never cause damage.
Do you have a tang already?
If you're buying from a LFS then I would have them hold it for you for 2 weeks before you bring it home. Make sure it eats at the lfs .
I really don't think I would have ever bought one if I did not get the chance to get this fish from a fellow reefer. You've probably read all of the posts about PBT's and I was always scared to try one.
I wish you luck
Jon