I have hunted with a versa max for six years now. Great gun, eats any thing you feed it, soft on shoulder, no failure of any kind. I have never shot a sx4 , but I have sx3 ultimate sporting, great gun also. I am sure the sx4 would be every bit as good.
I don't like 3.5"mag shells. But I hunt waterfowl from a coffin blind, set in a large group of big foot decoys. So most of out shots are 30 yards or less. They may be better for pass shooting, or turkey hunting. I find them expensive, heavy recoil, and at he end of the day can't say I kill any more birds with them. Just my 0.2 worth other opinion may vary.