BSA (Big Schwanz Acht) here...I had to create a new account due to some oddity that didn't allow me to log-in.
Anyway, similar to Bull, I used my Bathmate (I actually have 3 models) all modded w/the VacuVin exclusively until I purchased the MityVac with the goal of sizing the cylinder to restrict girth and apply as much force along the length axis...been using almost every day for 3+ years. My personal best is 21.5 cm and hoping to max it out in the not too distant future (although I've definitely hit a plateau over the last couple of months.
My $0.02 worth? Both the BM and the MityVac have their strengths/weaknesses (although the MityVac wins hands-down for convenience/comfort). I too struggled w/ball-suckage and my solution was to not fight it and I dscovered 'whole-package' pumping. It takes a bit of dexterity to allow them the enter the cylinder w/out sending you to-the-moon with pain, and w/the VacuVin hand-pump, modulating pressure is infinite.
75% of my pumping is in the MityVac due to it's superior convenience and ease of clean-up (I use virgin coconut oil for lube).