I concur with peartree--I think the vent rib is kinda neat. I put a cheapie Cabela's 2-7 Pine Ridge on mine and headed to the range. I wound up with 1 1/2 to 2 inch groups at 100. I had intended to get a better scope, and give her a good go, but fate interviened and I drew a buck antelope tag for ND. Pretty rare occasion, so I have been working with the 600 Rem in 6 mm, as well as the 257 Roberts for that.
After antelope season, I intend to get back to the 673, but for now, at least, I also agree that the recoil is manageable. I had a Browning BAR in 338 Win Mag that used to beat the snot out of me. This one I can handle, but you know you have your hands on some snort.
As far as ammo goes, Cabelas is the only reliable source. Bit pricy for now, but I have reservations about reloading a belted magnum case.
Heard a guy has a bushing out to go in the resizing die to resize the belt as well, and eliminate the splitting problem there. Any experience out there along these lines?