new preoduction sturmys are an overdrive,lers hear of some failures of the old ones,iknow numerous ppl whohave used these without a failure,if you start with a bad one exspect to have problems,there built way better than annyof the new stuff or the overpriced sachs
The modern S-RC3 3-speed model has the same gear ratios as the old 3-speeds did: 75% in L, 100% in N, 133% in H. You're probably thinking of the two-speed kickback, which is an overdriver. The S-RC 3 is a solid hub, but it's not terribly cheap. The modern hubs have made leaps forward in a couple areas: materials, braking, and electrical generation. I love old Sturmey hubs, but the old coasters were really a weak spot for them, compared to the AW.
On the old Sturmey coaster brake hubs, I've seen:
-cracked brake shoe base ring
-broken/torn central e-clip
-broken pawl springs
-torn brake shoe wire ring
-chewed up gear ring and planetary gear teeth
The classic case is the TCW that has gotten beaten because the E-clip migrated to the brake side of the hub, allowing the transmission half to free-float inside the shell. The hub will work enough that people try to ride them, but then it fails or slips, and finally they take it for work and it's damaged because they rode it with a loose transmission assembly.
And yes, some hubs come to you 'bad'. But too many are bad because of a mechanical failure followed by someone trying to run the hub. The best couple of TCW hubs I built-up took 4-5 parts hubs to part-together with the good bits.