I have the Schallers on my Fender American Deluxe ('93), I like them for the simple fact of when you change/break a string it takes only a few seconds to replace. Pull the string through very snug, clamp it down, and tune. No need to wind it 3 or 4 times. And I have no problem with it staying in tune like this. I haven't tried Sperzels, but I'm in the same boat because I want to put a set of locking tuners on my SG. Just don't know which ones I'll go with yet.