Rink I worked at used the blue stone (8MXR) for the longest and I loved it. They switched to the pink stone (88R) for a little and I'm not the biggest fan. Seems like I had to redress the wheel a lot more often. I'm now using the green stone (8GC). It's a good stone that holds up. I don't do a lot of sharpenings (mine every so often and maybe a few teammates), so I'm still on the 1st wheel. The EQM that I bought the machine off gave me a whole box of Ruby wheels. I might throw one of those on next.
For now, I'll stick with the green wheel.
Unfortunately, haven't tried anything but the blademasters