10mm
What is the expectation from your 10mm pistol?? This is the important question.
If you are going to shoot a lot of full power rds and or beat the crap out of the gun the G20 is the best bet. Typical Glock tough, designed from the get go in size and shape for the big 10mm.
If I was going to have a 10mm for carry, hunting, then the 1911 is my 1st choice.
Hand size and whether you can grip the big Glock frame is a deal breaker for most.
Doesn't matter what I do or how I hold on my hands can't get a decent pruchase on the Glock for even the 1st shot....gets very ugly on each multiple shot after.
The 1911 is a pure joy for my hand size and shooting style.
A PROPERLY built and setup 1911 10mm is a great pistol.
The gun needs a ramped/supported bull barrel, proper springing/buffering, and optimally a longer slide than 5in.
The Delta Elite in stock format is crap. The ridiculous multispring/plastic mousetrap coupled with the conventional unsupported unramped barrel is silly.
Spring and tune the gun for the pressure and slide velocity of the 10mm and it gets good. Longslide the gun and or comp it and it gets VERY good.
I had a Delta built with a ramped bull barrel, comp running a 24lb spring. SUPER pistol.
So if you want an off the shelf 10mm the Glock is prolly one of the only choices. I would think the STI 10mm must be a nice gun but I haven't shot or owned one?? I think they make a longslide 10mm which must be a great shooter?