Haven't used one of those before. You're right at the top (84V peak on 4.2v a cell and 20 cells), so if you add any later, you'll have to get another...
I started selling to you guys quite a while ago (2009 maybe?) whenever I'd find good deals on used equipment. Sometimes I made a few bucks, sometimes...
I think the Magura feels cheep, and it's not very springy, and the throw is way to long. I never tried domino, but it sounds shorter throw and better...