It seems to me that even though you might be discorded to say 60s in something, the gains don't really go up like you are in the 60s. Still for things like tailoring I would say 17 of cloth is much easier to deal with than trying to do it at home with tons and tons of leather. This is the real benefit of the trick but still the gains do seem to be slow but for some reason not as slow as it would be if you were trying to gain at your real level. I can only speak through experience though and this is not based on any indepth study of gains.