My take on HTII bottom brackets.
The shimano ones last about 12mths for me
My first SS model lasted 6mths then went all wobbly/gritty. Keswick MB’s were doing my drivetrain and the nice mechanic actually repacked the BB out with fresh grease and it got to about 14mths without issue before needing replaced. I have since bought another one and packed it out from new. 6mths on its as fresh as a daisy. I may just repack it with grease soon to ensure it keeps going. I have no complaints with the SS ones as long as they are kept greased.
Now onto replacement bearings. I have done the replacement SKF & Enduro/Betd bearings thing. Both lasted approx 6mths before going the way of all the others. Repack and you get 12mths. The PROBLEM with these replacement bearings isnt in the lifespan, its in the fact that they do away with the tophats. That tophat protects your crankshaft/whatever from wear when the bearings start to grind/sieze. I noticed that on the aftermarket bearings my lx crankset got a hell of a wear right where the shaft was running on the bearing. Check your cranks!! Not saying its too bad but if i was running the aftermarket ones now i wouldnt risk them getting slightly stiff as they gradually do as this will be grinding metal on metal.
Personally, SS bb with a repack every 6mths is good for me.