I've handled or owned custom 2011's from most of the custom makers out there. None of them are close to an SV. Fit, finish, and quality are far above anything I've seen assembled with STI parts.
2 years ago, I held an SV sight tracker that had upwards of 80k on it. It still felt as tight and smooth as any custom 2011 I've handled. I now own 3 of them and don't plan on selling them at any point.
As far as the actual shooting of a sight tracker configuration compared to a conventional barrel, it's different. With the sight tracker, the slide is very light so actual muzzle rise is low. It also cycles very fast. My best comparison is with 9mm minor guns. A conventional slide gives more of a push then recovers. The sight tracker more of a light snap and recovers quickly.
If possible, try one before buying. It is an expensive investment but it's worth it to me.