No one has any input?

Well, I don't have either one, but I do have a .40 Glock 27 and I know that the .40 is a shortened 10mm and the .357 SIG is a necked-down .40. If you're looking for max "stopping power" (whatever that means now-a-days lol) then look no further than the 10mm. It only makes sense that a shortened, necked-down version of a cartridge would not have the muzzle energy of the original, but I hear the .357 SIG is a mean round, and I certainly wouldn't want to be at the wrong of it. It's like a 9mm on steroids, but I don't think it's as mean as the 10mm. I'd love to have both!!

I wonder how the recoil on a Glock 20 compares to a Colt 1911.

Again, I haven't shot a 10mm, but I have shot a Colt 1911 and I own a Glock 36 (both .45 ACP of course) and I think there is quite a difference there. My point being that the Glock polymer frame will absorb some of the felt recoil, whereas a steel frame will not. On the other hand, the Colt weighs close to (if not more than) 40 ounces, and the Glock is fairly light, so the Colt has the recoil-dampening weight going for it. That said, I would say that the Glock 20 and the Colt 1911 would probably be fairly similar as far as felt recoil, but I'm not sure. If you can, the best thing is find a range near you that rents both guns and shoot them side-by-side. I know I've made expensive mistakes in the past by not shooting a gun before I bought it.
Nothing at all against XDs, but I traded my Glock 19 in on an XD9SC because I loved the way it felt in the gun store. After I'd shot a few hundred rounds through it, I ended up trading it straight up for a lightly used Glock 36 that I carry today (also my G27 sometimes).
In the end it's up to you, and it depends on what you're going to use the gun for. Nutnfancy (I hope I spelled that right) on YouTube has some great gun reviews and one of the key points he has that many others don't is what he calls "P.O.U." or Philosophy of Use. How will the gun be used? Is it a nightstand gun? A hunting companion? Are you going to carry this every day of your life? Will it be just for fun at the range? I'd say go for it if you can afford it and you have another weapon to serve other purposes, such as daily concealed carry. On the other hand, if you can carry open in your state and choose to do so, the Glock 20 might be a good choice for you. So many variables and so much rambling on my part, but I hope this has helped a little

Once you shoot a G20, you won't be able to live without one. I'm not a big Glock fan, but I love my G20. Recoil is very controlable and does not have a snappy kick. Throw in a .40S&W conversion barrel and it feels like you're shooting a .22lr.

Originally Posted by 10mm Sonny

Once you shoot a G20, you won't be able to live without one. I'm not a big Glock fan, but I love my G20. Recoil is very controlable and does not have a snappy kick. Throw in a .40S&W conversion barrel and it feels like you're shooting a .22lr.

How does the recoil of the Glock 20 compare to a 1911?

I've never fired both on the same range visit, but I would say very similar to each other. IMO, it pushes straight back like a 1911-45, not a snappy up-kick like a .40S&W. My G19 9mm feels snappy compared to my G20. As I said, once you fire one, you'll be hooked.

On a side note, a lot of 10mm ammo is watered down. Especially the target/FMJ ammo. Even then I really couldn't feel a difference in recoil between CCI Blazer target ammo and fully loaded Buffalo Bore GDJHPs.

I'll be going to the local range to rent this bad boy...

10 mil will rock ur world

i'm not sure you can really compare the recoil of a glock to a 1911, i don't even find the recoil to be the same between different 1911 manufacfturers and models. I find that the glocks i've fired have a more straight back recoil then 1911's which really makes it feel different.
they're big rounds they recoil, you get used to it, and if your big enough to hold the gun i don't think it will knock you over.

The recoil on my full sized 1911 RIA was worse, harder to control and made my arthritic hand hurt, G-20 & G-29 does not.