I have had a pair of these put on my bike about four weeks ago, and they are the fastest grip to get worn I have ever seen in my life. Grip is all right, but my hands sometimes start to hurt.
In terms of wearing off, their name suits them well: SHIT !
As any lock-on grip, they never leave the bar and seem to be glued to it. No problems there ! Their ends are metallic, and are pretty tough. Even though they look really nice when put on the bike and are one of the cheapest lock-on grips, I do not think that I will ever find myself buying a pair of these, when I can get some Sunline grips or whatever.
Full width Carbon bar for DH racing or Freeride

The Features of the Gravity By FSA Carbon DH Bar are: