Weirfan ahhh ok. I'm almost done with my 2nd cartridge. It's probably 2 years old, and it's still holding everything I use it on. No failures at all. Then again, I sand everything with 220 grit, scrub with 90% isopropyl, mix the epoxy really well and apply.
For reference, over the last few range sessions that I've fired up my Mevo, my swing speed has been 100-116 with my driver; mostly 110-116. Smash is around 1.20-1.40, so not that great.
