I thought that green gas is pressurized lower than propane.
I think one of the green gas containers is pressurized at 115 psi and a tank of propane at 130 psi.

Anyways, shouldn't really matter that much if you tune your gun to handle the high pressure gasses. As Drake said, the only ones you should worry about is the Japanese guns with plastic components for green gas. Even then, depending on what the gun is, they generally last a while on GG

Thanks for the replies everyone.

After reading all that, I think I'd better stick to Green Gas because I'm mostly just shooting in my basement and I don't think any of the other people in the house would enjoy smelling propane....and there already isn't enough ventilation for the heat, let alone the smells...