Hi JamesB,
Your new rifle sounds nice......I'm jealous!
Give us a field report when you get a chance.
Back40,
Get the rifle in the caliber you like! There is little enough difference between the two cartridges that maybe 1 in 10 people could "hold the difference" in the field. They are both good cartridges.....they both have their merits. In all honesty.....the .270 WSM looks interesting to me. But if I were putting out the extra cash to get a really nice rifle I'd be inclined to get the .270 Winchester. Simply because it's classic......has and will be here for a long time......and the .270 WSM is new enough we don't know for certain how a "fickle" consumer market will......or will not.....accept it. The .270 Winchester will be here for certain.....long after we are all gone!
Good luck with a tough decision!
Dave