Yeah its quite good stuff.
However it takes a very long time and a large amount of mats to get skill to 375.
You'll invest many hours or thousands of gold to get the set. And the only thing you get is three pieces of decent armor.
Furthermore you have to stick with a profession which will not provide you with much money.
An other thing is that this set is not that great. It is better than most/all blue items obtainable at level 70, but there are better epics you can get from raid instances. So if you raid somwhat you'll replace that gear after a few weeks or months.
Acutally the bracers are not that good. With
Stalker's War Bands you can get an equally good item from the 1st boss in Karazhan who is a real joke to do.
For the belt you can find an equally good item (
Girdle of the Prowler) also from Karazhan, however a bit later, from Terestian Illhof, the 7th boss in there.
Only for the breastplate there does not seem to be an upgrade available in 5man heroics or Karazhan.
All in all for me there is no reason to pick up leatherworking for those items, and for making money leatherworking is not the right profession.