I've used a Sturmey-Archer S3X hub for several years now on my "bad weather" bike. I haven't had any problems with it, and have put plenty of miles on it, including several rainy 100+ mile rides. As others have noted, it's probably not a good idea to rely on it for all your braking needs, although I've had no problems using it for typical fixed gear speed control. The gear ratios are not ideal, IMO; I'd rather they had used the 0.75/0.9/1.0 ratios they used on the old ASC 3-speed fixed gear hub. You mention a Shimano hub with gear ratios you like. Which model is that? I'm not aware of any Shimano 3-speed fixed gear hub.