I shot one a couple years back but was only out to just over 300 yds. I thought it was cool for what it was and can appreciate its purpose. The ammo was just surplus stuff we picked up real cheap, it was accurate enough to hit the paper plates that we were shooting at. Would I buy one myself? Sure, if I found one in the right price range I would probably pick one up.
Enjoy your new rifle and like 6xcKY said, watch for that corrosive ammo.