Any of those caliber choices would be pretty good all around big game cartridges. I wouldn't consider any of them good varmit choice if many rounds will be fired per outing. Such a Prairie dog hunting. Of course the 30 caliber is going to be the most versitile of the bunch because of the wide range of available bullets. I wouldn't consider any of the WSM's unless you intend to reload for them to take advantage of all the available bullet weights. I don't think the 7MM WSM will survive in the market place so I wouldn't consider it for MYSELF. However thats just my opinion from watching the sales of these calibers. Up here the 270 and 300 WSM's are selling well but almost no-one is buying the Seven WSM. Of course there can be no talk of ALL AROUND rifles without including the 30-06 which has filled that niche for over a hundred years. Since 1903.