Stone Training

anyone ever try the stone trainer that elitefts has or something similar?

http://www.flexcart.com/members/elitefts/default.asp?m=PD&cid=305&pid=2640

i don’t have stones and was going to make something like it to train for them, was wondering what kind of carry over there is, like is 200 on “the trainer” the same as a 200 stone? or is it easier or harder?