I bought the Browning Maxus. It is a gas system. The thing is light and has no issues with different loads. I have mentioned in other posts that I take it to the skeet field and fire 2 3/4in #8s out of it and then take it to the duck blind and shoot 3in #2s out of it. I have even shot 3 1/2in BBs out of it. I have heard (haven't shot one though) that some of the inertia guns don't like light loads.
The Browning Maxus breaks down and cleans real easy. I don't shoot as much as a lot of people do but in less than a year of owning it I have 600+ rounds through it and haven't had a problem. Again it is easy to clean and as long as you actually clean it there are no issues
My idea of fast food is a mallard.