I have both a Remington 673 in .350 RM and a M98 in 9.3x62. The 98 has a 25.5" tube, so the two rifle are very different, in terms of ergonomics. My 673 has had the rib removed professionally by the previous owner; I like the modification very much.
I've only shot one head of game with either rifle (a pig with the 9.3), but I hope to use the 673 in the next couple of weeks on some more wild pigs. FWIW, I really like the 673. It is one of those rifles that just **feels** good. I can't speak to performance on brown bears, but both rifles and cartridges have reasonably moderate recoil and I think that you'll be satisfied with either. There are more components available in .358 caliber than there are in .366 caliber. If you're willing to wait for mail-order, it's not really a problem.
