260 has short action, slightly less recoil and would be outstanding deer size game cartridge 120 to 140 gr bullets. If you reload, lighter varmint bullets are available in the 85-100 gr range. I shoot 87 gr speers out of my 6.5 x 55.
280 has long action and is a good deer, elk, black bear cartridge. It falls between the 270 and 30-06 and will perform and recoil very similar. If you reload, there are a lot of choices in in 7mm(284) bullets from 100 to 175 gr with 140 to 165 being the most popular in factory ammo.
Both are great and you would be pleased with either. I would vote for the 260, but I am a little biased. I love that brass, 243, 260, 7mm-08, 308.
Good Luck