Should I slice this?

I'd slice it because there is only the flat health as the worst possibility, and even that isn't bad for a health set, health primary mod. I'd be hoping for any of the others though. So 75% chance of happy, with 25% of extra happy with speed.

It really depends on the state of your collection though. Is 15 speed decent or trash to you right now? Would the supreme roll of 6 speed just give you another ok 21 speed mod, or do you only have a few 20 speed mods right now? This is all part of the decision.

Personally, at the moment for my collection, a mod wouldn't even get to 6e without having 15 speed at that point. Except for more specialized mods.

It's a pretty darn good SEE mod. Once you get him, put that mod on your SEE and finish slicing it.