Yeah, I got a couple of each laying around, and I'm waiting on parts to proceed with the F/X so I thought I'd tear into these...
Side by side you'll see the differences and weak points, (of each) and be able to make an informed decision if it's "strong enough" or if you can trust those little keyed shafts...
They work just fine to a certain HP and RPM and Weight (torque) requirement...How much more will they take before you need to upgrade for your requirements...??
I'll let you guys decide...