Burgie,
You won't regret going to the 7-1/2 HP compressor. I installed one about a year ago. I had used a Sear 6HP oil-less prior to that.
The difference when sand-blasting is like night and day. I can run my blast cabinet constantly at 80psi and the compressor runs less than half the time. Before, I would have at most 45-50 pounds at the cabinet and the compressor would run constantly.
It makes the whole process of cleaning parts a lot less like work.
