The 45 ACP is my favorite defensive handgun cartridge and I have alot of experience with it. I also own two 10mm pistols. Yes the recoil is more, the penetration is more in the FULL Loads, but most 10mm loads on the shelf are wuss loads and kick no more than the 40.. I have used the full power stuff to take several large wild hogs and one small deer. I know several Game Wardens that carried the 10mm and swore it was the best all around cartridge for their type duty. I also have several boxes of Buffalo Bore heavy Duty ammo. Some very potent stuff, with the ability to take fairly large animals. I guess if I had to be armed with a semi-auto pistol in Bear Country, it would be a 10mm with Buffalo Bore Ammo. (not my first choice, understand, but better against bruins than a 9, 40 or 45)
When the 40 was developed out of the lighter 10mm loads, the 10mm popularity started dying out. But that doesn't mean it's not a practical cartridge. My Glock 20 feeds the full powered and light loads equally well. That gives it a little more versatile life in my book. Is it my first choice? No, but it's a great cartidge when you realize its' potential and versatile possibilities.