IR ThunderGun Impact Wrenches any opinions?

I was looking at getting a IR 231C impact wrench because of its affordability and I have heard its a pretty good tool for what I would need. I was kinda thinking I didn't need a high torque one because on the rare occasion I would need one I would just go borrow my brother's like I normally do anyways. I was looking tonight and I see IR has this ThunderGun in which they have all advertised up, as being just like "Nascar". Its advertised as a 625ft-lb gun but at half the price that a 600+ lb gun usually run for. Are these thunderguns just marketing hype or are they a pretty decent gun?