Better action with wood-plastic hammers and backchecks?

[thamesman]

Just wondering if anyone has an explicit preference of the tonality of wood-plastic hammers (those used on '74 and early '75 models). I'm currently looking at acquiring a '74 with these strange "hybrid" hammers. It sounds really good and the action is not stiff at all (the owner did a mod to loosen it), but I don't like the bounce-back on the action due to the wooden keys with lack of backchecks. The action feels kind of "sloppy" and it's difficult to play notes in rapid succession because of the hammers bouncing. Also, the keys have significant side-to-side play. Basically, I'm wondering if anyone has had good/bad experiences with cleaning up an action with backchecks. I like this piano and it sounds good, but am I going to be stuck with bouncy, uncontrollable action?
Thanks.