Seeing the results from hunting I just really can't buy the penetration only argument, even with handguns. You have to have the penetration, but achieve the same penetration with a higher velocity and different things seem to happen. Gel, while a good way to compare loads, seems to be too homogenized to capture the damage that occurs.
Regarding cost, I can plink with 357 sig at the same price as I can with .40. More expensive than 9mm, but cheaper than .45acp.
I like it and I'll stick with it.