Not only cartridge differences, but the gun weighs in
My friend has a 500 S&W, I have a Super Redhawk in 454 Casull and a Freedom Arms 454 Casull.
I prefer the SRH over the other two. Why?
I had a couple S&W (K22 and Model 28). I took the sideplate off the K-22 once. Cleaned and oiled it, reinstalled the parts that sprang out when I opened it and never took it apart again. Traded it off shortly thereafter. The thing had twice as many moving parts as my Dan Wesson and I understood the DW operation a lot better than the Smith. The parts in the DW were more robust and have never broken. The parts inside my Rugers are even more robust than my DWs. So that is why I prefer them over the Smiths.
Not so my friend's S&W 500.
I have, several times, posted my regard for the 500 S&W cartridge and my desire to see Ruger offer an extended frame Super Redhawk in that chambering or even an extended cartridge 5% more powerful than the 500 S&W. I would call it the "500 Bill" after Bill Ruger.
Having mentioned one-upmanship, many people have bought the X-frame Smiths just to have the most powerful production revolver on the planet (the Pfeifer-Zaliska .600 Nitro Express really doesn't count in my mind). If that is part of your desire, go for it. The 460 matches the energy level of the 500, shoots farther, flatter and falls back only in the heavier bullets. It is an excellent choice.
Despite buck460XVR's testimony, I contend the accuracy of the two chamberings is equal. I know of no one who has done the testing of enough different guns (Smith or SRH) to categorically say either is inherently more accurate. Individual gun vary in their accuracy, so maybe buck460XVR has seen and tested a few SRH's that did not compare to a few Smiths, so I do not doubt his veracity, but my SRH matches the accuracy of my friend's 500 pretty well. (Though I admit my statistical sampling consists of just the two guns, so is not enough to make a general statement). I do know that Smiths do generally have a superior double action trigger, new in box, where the Rugers do better after a few thousand round (a number that will put a lot of Smiths into the repair shop). My FA 454 Casull, with a 4.5" barrel and fixed, small sights outshoots both my friend's 500 and my 454 SRH.
So, back to the original question. The .460 S&W (as well as the 500 S&W) deliver about 40-50% more energy at the muzzle than the 454 Casull and the weight of the gun (and the muzzle brakes) help with the felt recoil. I believe accuracy is equal between the two guns (and cartridges) if you are. A chest holster arrangement mitigates the weight concerns greatly (and makes sitting down in camp a LOT easier) though complicates your backpacking a bit.
So, the choice is yours. Accepting more weight and costing couple hundred dollars will get you the more powerful Smith X-Frame 460 S&W. Less money, less weight at the cost of less power (but arguably more durability) will get you a 454 Casull Super Redhawk.
With either choice, I STRONGLY advise you to take up reloading. My friend loads 500 S&W for a quarter of what factory ammo costs and he can load so light you can see the bullets travel downrange at 500 fps all the way up to Buffalo Bore power levels. It really help, when at the range, he lets others shoot his cannon, starting with the lowest power levels and letting them work up to whatever level makes them say, "enough". The first test, of course, is if they can actually lift the gun off the bench.
Good Luck
Lost Sheep