Well I am a huge fan of the .280 and I have never owned or even shot one. Someday I will also build a full blown custom rifle, and I do mean full blown. Not a single element will be standard factory gear. Even the bolt handle will be unlike anything being offered from nesika bay.
Almost everything I have learned about the .280 is positive. The energy is good for LR deer and elk. The accuracy is good for very LR coyotes and chucks. The recoil is not sharp or as harsh as the 7mm rem mag. The accuracy of the rounds being fireformed is often sub MOA. This allows having the rifle for a season and using it as a regular custom rifle while forming a boodle of brass then the following seasons the accuracy is likely to improve from having brass formed to your chamber. Throat life is good and in a pinch (you forgot your ammo) you can buy factory .280 rem ammo off the shelf and continue the hunting trip.
I have heard that the round really comes to life in a 28" or longer bbl with 32" being the "magic number" in a 1:9 twist. Loads using a 140gr to 160gr ish bullet seem to be the cats meow for this chambering. But that was before Wildcat Bullets came along. /ubbthreads/images/graemlins/laugh.gif
Dang it! Now I'm all lathered up about that project again. I can't wait to begin working on that gun but as it is I already have many irons in the fire.(And the family wants a hunting dog now. I really need about 30 hours in a day but only 8 days a week.)
Aaaaaanyway. It would be better for a guy who calls himself "Long Action" to have the AI instead of the 7mm short, fat, squatty, wide-bottom, pin-head shaped, mangnum.