I had the .480 Ruger in a Ruger Super Redhawk and then also in a SRH Alaskan (6 shot). A few years ago, I saw the writing on the wall and traded them both towards their .454 Cassull counterparts.
I also had a .500 S&W, and traded it towards a .460 S&W Mag, although you are 100% correct that these make very poor defensive wheelguns. Too big, and way too much recoil to be weilded effectively in a self defense situation, and if a bear can withstand 6 shots from a .454 Cassull, he's not going to be stopped by 4 shots from a .460 S&W (for the life of me, I can't draw and shoot more than 4 shots from the .460 in the same time I can fire 6 shots from the .454, and my groups aren't as good either. Measured with a Pact Club 3).
The .480 Ruger Alaskan would have been my ideal bear defense weapon if I had confidence the .480 Ruger wasn't going to get phased out. Unfortunately, they also must have had some issues with the 6 shot .480 Super Redhawks, so the more recent models have been converted to 5 shot cylinders, which was kind of a disappointment, since the SRH was known for being a 6 shot when its competitors were only rolling 5.
Personally, I got out while the gettin was good. If you found a good supply of .475" bullets or a steady supply of .480 ammo, then yeah, I'd highly recommend the .480 Ruger for a defensive weapon, as well as a decent choice for handgun hunting. It has very mild recoil compared to the .454 Cassull (closer in recoil to the .44mag even though its energy is closer to the Cassull than the .44mag), but has incredibly good stopping power (higher Taylor KO factor than the Cassull thanks to that big ol fat bullet). But if you can't find ammo or bullets, then I'd recommend the safer choice, the .454 Cassull.