My two Deagle's. The black is a Mk. VII in 357, the matte chrome is a Mk. XIX in 50ae. Had another black 50ae for a short time before finding the matte chrome one. Never had a 44, it's on my want list. I've shot the S&W 460xvr. Here are my thoughts on it all.....
All depends on what you want them for. Are you wanting a practical large bore high power gun for deer and other game hunting? Get the 460xvr. With the longer barrel, slightly smaller slug however with the higher velocity, gets a much flatter trajectory and better range for taking game at medium to not overly long distances for pistol hunting. I take my 50ae along with me when I go deer hunting, but as a sidearm backup in case a close opportunity presents itself. I would not try to take a deer with it more than about 50 yards away, and that's even pushing it. Although I could likely get a hit at that distance or a little more, it would have a high likelihood of not being a very clean hit. I did have a deer once about 10 yards away from me, perfect range to try it out and say that I had taken it with a handgun, unfortunately it was on the wrong side of a creek on non-hunting ground. So never taken a shot with it for game, but always take it along just in case. And that being said, it's not bad to carry around unless I suppose you're really small or weak, in which case, maybe a gun like this isn't for you!
Now, if you're wanting these things for just big booming sh*t eating grin factor at the range or blowing up reactive targets, that's what mine are mostly for, and for that, they are wonderful! Very little else brings an ear to ear grin to new and experienced shooters. At least for me, they've been very reliable, if the right ammo is used. The 357 can be a little picky, I found that Magtech 357 worked great, but I reload everything for both of them now, and my loads don't miss a beat. The 357 is very controllable, with as big and heavy as the gun is, and as much of the energy that's taken up in recoil, after the shooter gets over the mental block of it being big, it really doesn't kick more than a 1911 or a plastic frame 9mm. You do have to have a firm grip on it. In either caliber if you limp wrist it and let motion of your hands/wrists/forearms absorb too much of the recoil, it will jam, gotta have a nice manly grip. That's my usual problem when handing either to an inexperienced shooter who's a little timid, they'll jam the first few rounds, I tell them to man up, and it's smooth sailing from there.
The 50ae is a nice step up, can definitely feel the increased power, but again, because of the size and weight, it's still very controllable. Limp wristing is a problem again, but I can shoot it one handed, standing off hand, and it works great and can usually hit a metal gong at 25 yards. If you're going for just one, and just for fun sake, I say go big or go home, get the 50. In any case for any of the calibers, I highly recommend reloading so that you can shoot it care free without worrying about the cost.
Back to the S&W, like I said I've shot the 460, and for hunting, would recommend it for it's superior ballistics, however I myself want the 500. The S&W is a whole different beast to shoot. Being a revolver without the slide action to take up recoil, it hits you like a punch in the chest from the shockwave, sounds unpleasant, but for someone who likes a big boom, it's dang near erotic. Again, for mostly the joy of the boom, I want the 500 just cause it's the biggest baddest a$$ thing out there.