Unless you like to tinker, I'd stay with what has worked for you, and here's why - oh ya, I've owned more than a few in factory and wildcat form, as well as hand loaded for guys in all the WSM's and many of the wildcats, and like them - but then I like most guns and cartridges!
The short action thing is highly over rated IMO, unless a person wants to save every ounce of weight they can, and even then, they could likely do it in a light caliber, and the faster bolt cycling won't matter in a hunting situation.
the WSM's are not that far away from the standard magnums and such as far as velocity goes, and some have quirks such as FL sizing that some shooters do not find desirable.
Unless you handload, you may have trouble finding the cartirdge and bullet weight you want, and prices can get expensive.
You will get no more accuracy oput of a WSM than any other cartridge.
so, if you want a new rifle, and have to have a WSM, go for it.
if you want a new rifle that is some kind of weird laser beam killer, all you have to do is practise a bit more with what you have!

Cat