For a 950SM-- the correct battery would be an Antigravity YTZ10-12; correct?
My original Yuasa has lasted almost 7 years. The bike doesn't sit a whole lot (and hardly ever for more than 3 weeks), is/was always on a tender when not being used, runs heated gear in the winter (vest, gloves, and sometimes socks), and never had any issues. So you can say I am pretty satisfied with it, and it's hard to beat that price/performance.
I do like the weight difference, but it's not as critical with the SM compared to the SE (the SE has to be picked up a lot
I have a Shorai in my 950SE for over a year and it works fine so far-- started the bike in the 20's last winter with the proper warmup; runs the same heated gear as above, never on the tender. I'm curious to see how it fares this winter.