...they are far less prone to just scattering when you've removed the trees for some reason other than working on the balls and races.
Never had that though ;-)
Conditions of head bearings is a
mandatory inspection point during the annual MOT, and since I'm pretty observant I get them done on even the slightest sign of "locking" in the centre position anyway...
So I yet have not seen any balls flying through the work-shed... but my mech surely did, sometimes they get real worn down, rotten vehicles in...
What I lack is the seals and those are not too bad getting oem (but have not gone to a seal and bearing distro yet so who knows there).
Just because of that seal issue (only cover plates) I never really bothered with tempered... IIRC were there issues with the seals when fitting tempered bearings?
The OEM ones come as a kit in a funny cardboard-can like instant coffee, top and bottom bearing plus the two seals/covers... no hustle, no searching around... just remove the forks, bang the old bearings out, reach into the box for the new parts... 2~3 stress free hours...
What I dislike on doing head bearings is that I could loose the MOT- plus the m/way toll-sticker... both placed on the tubes, just below the upper TT...
Have to wedge a large screwdriver into the gaps of the lower TT to widen it enough so them stickers don't get scraped off... fumbling like a surgeon there... ;-)