"Do these STS systems that mount in the stabilizer hole work?" YES, they work exceptionally well which is exactly why manufacturers like Hoyt are scrambling to produce a factory standard model. They are NOT gimmicks, they actually soak up shot vibes like a sponge!
"Do they wear out your string?" No, they are not that hard on the string at all. In fact many different models don't experience even any fuzziness of the bowstring. However, to prevent any wear they do aupply a small amount of serving to wrap around the contact area of the string. Wear just isn't anything to worry about.
"Does the front mount option still allow you to have a stabilizer?" Yes, it's a simplethrough bolt design that allows you to screw the stabilizer straight intoit. Honestly,I have NO interest in shooting a rig that isn't equipped with an STS.
Here's my STS front mount equipped Trykon