I've owned a P220 in 45 Auto and loved it, but sold it (Elite Stainless). At the time I didn't "see any use for it". So, it wasn't a 10, but I'm very confident the big Sig would make an excellent 10mm for sure--if you're okay with the single stack thing.
As for the general question of a 10mm auto pistol, you know they vary widely in size, weight and capacity, so it's really going to come down to which 2 or 3 do you want. I carry the G29 and for me, it's an excellent carry. It's not the most comfortable handgun I own, you need to be prepared to practice enough to really control it, and I find the trigger to be okay and good enough for a carry (I have an after market 3 lb in it, and pull is longer that stock but okay).
Someone asked about brass damage, and I'd say yes--you're not going to be happy with Glocked brass coming out of that thing with the stock barrel. I have the full length case squeezer die, and I'm sorry--there's no full recovery of the brass. You can still fire it again, but it's ugly, permanently damaged and a sad, sad thing. In my experience with Starline brass, that stuff is pretty much like butter--with loads near published max (you only have to get close--you don't have to be at or above max) and the brass squirts out of that chamber like Play-Doh.
I also own a G20 and don't really shoot it much at all--it's even less comfortable than the G29, and is just kind of a so-so gun--great nightstand gun, I guess, if you're okay having an unholstered Glock on the nightstand. I'm not, so it pretty much sits in my desk drawer.
The nicest feeling, handling and shooting somewhat 1911-ish doublestack I've ever fired is my Witness Hunter, but I don't believe they import them anymore, and the triggers on those are a bit goofy. But, the grip is less than 1/8" wider than a gov't 1911 and or my medium hands and short fingers, it's actually quite a bit more comfy than a 1911 to me--which is saying a lot.
Now, for a doublestack 1911 that shoots well and that I can afford to actually own, I've had my Rock Island FS II for about a year now, I think and love it. It's not without a few issues, but I'm happy to work through them, especially given the price. I'll go thru the negatives first:
The front sight is a fiber optic--I hate fiber optic sights, but this isn't a problem for me because after about 1,000 rds, the little fiber optic thing fell out of the sight, and now it behaves like a decent front sight. Problem solved.
The magazine design doesn't accommodate handloads with a coal as long as I need to load for the glocks--I have to seat a good bit shorter to get the magazines loaded and for them to feed. Again, this is really only an issue if I'm running XTP or similar bullets, and I have not had issues setting up my favorite round nose flat point cast, or Gold Dots.
Sharp edges and corners. This thing has more sharp corners and edges than you can shake a stick at, and I found that after a couple hundred rounds, I sure could feel it. I've addressed this by knocking off all the pointy corners I could find (around the safety lever(s) and the grip area near the safety, and the magwell at the back strap).
Those scalloped G-10 grip panels--yikes. Not sure who thought shooting a gun with a snow tire for a grip would be a good thing, but I can tell you that after a few hundreds rounds in a session, those scalloped grips just chew my hands up pretty good.
That's it. These would be more serious complaints for some shooters, for me they are not big issues. I've corrected the issues that bug me, and can replace those grips.
For the positives--fit and finish are excellent for my tastes. Black, matte, no writing, no two-tone crap--just a matte black pistol. I like that. The gun is quite comfortable for a somewhat boxier-than-necessary Caspian-style frame, but I prefer somewhat fatter grip anyway. I find it comparable to a G20 that way, but far more natural feeling.
The adjustable rear sight has stayed put since I got the gun, and the gun is as accurate as anything I've fired in 10mm.
I'd buy another one, if I needed another 10mm auto pistol. I think it's a very well-made 1911 at a price that, for me, is reasonable.
As for the legend and lore of 10mm--yes. This cartridge seems to have an amazing amount of expectations far in excess of what is reasonable, to me. There seems to be an abundance of shooters who truly believe it is or should be a 41 Magnum, can be loaded to well beyond any published specs, and is basically a polar bear stopper. My recommendation would be to look at a) the published SAAMI recommendations for pressure, bullet weight and MV, and b) look at published load data where the peak chamber pressure is published. Compare. It's a great auto pistol cartridge--it's not magic. I've loaded maybe 10,000 rds or so for it, and with my problem powders such as Longshot, I don't have to get very near max loads to have primers falling out of the stretched case heads after firing. So far, I've found AA 9 to be The Perfect propellant for 10mm...nothing else I've tried comes close for clean, accurate and excellent performance within spec pressure.
