Whoa, seems this is getting a mite testy and that is too bad.
I see a LOT of the numbers game here and often by guys who should know better or by a couple who seem to get nasty in almost every thread, ( NOT Bob) and find it just sad.
I find the 280AI interesting, the Kimber MA seems a sound choice for mountain hunting and have loaded for and shot a fine custom Dana Campbell 7STW, did not care for certain aspects of the round and thus did not buy it.
I have NOT used a Mashburn, no reason to at my age, but, have found Bob's posts on it very interesting and he KNOWS his stuff on rifles.
I think that each should use what 7mm he pleases, I currently have seven fine rifles in .284 bore and three in .270, and like them all.