I just read your post on WW in the Malibu vs. Axis thread. Now you're looking at Supra huh? So can you share with us what the Bu lacks that you're looking for in terms of options/creature comforts/trim or what?
I own a 2008 21V with the Gravity III ballast system, which comes with two 400 lb. bags for rear lockers and one 650 lb. for the playpen locker. I love the pnp option. I also see the benefit of a hard tank but I don't have any experience with this, my friend owns a VLX and I've been in and ridden behind his boat. He doesn't put any extra weight in though on top of the hard tanks. I am planning to upgrade my current bag setup to the 750's for the rear and an 1,100 for the playpen locker. I've only one complaint, but it's not really that big of a deal. My bags fill fine, however when I drain them the rear bags do not drain completely UNLESS I engage in forward and do about 11-12 mph to get the bow up in the air and allow gravity to push the water to the back of the bag at the outlet drain. This method drains my bags practically empty but not bone dry.
After a day of riding, the next day I always open up the lockers and pull out the bags to air out the compartment and dry the bags. This is more of a precautionary measure because I keep the boat on the trailer during the week and it's at my fathers house about 20 minutes away, so I can't really just walk outside to open up the boat if I wanted to at any time. This helps to prevent mold from forming while sitting under a covered boat for a week.
Other than that minor nuisance, I really enjoy the bags and am looking forward to upgrading. I don't think 1,100's will fit right in my '08 lockers so I opted for the 750. I know that folks with 09+ models are able to fit the 1,100's easily, and if you're looking at a 22ssv then you'll have a bit more space.
Are you looking at a brand new one or used?
2008 Supra Launch 21V - Currently for sale