The only way I'll ever install a custom OS is if I cooked it up. Since I never felt the need to spend all that time doing that, I'd rather not. Other people's customisations are usually shit. Newbs thinking they are pros do this and fuck up a lot of times and ever bigger newbs download it.
You'd rather do the customisations yourself to be sure imo
The only custom OS I'd install is called.. well I don't remember but its from some release group who downloads all the latest Windows Vista Updates, merges them with the ISO and uploads it. Thousands of non newbs get it monthly so if I ever need it (not that I ever will), I'll use that