I love Reptibark. Easy to scoop out when he messes. and a little water on it in a corner and big time humididty, doesn't mold, looks and is natural.
To me the carpet thing seems more work. Take pc out, put new pc in, wash pc, let pc dry. With the bark i just scoop out bad. wipe, spray a little Virosan on area and forget about it.
But it's a prefernce thing because both will do the job just fine and both look good.