They say they like the Glock 20 because of the number of rounds it holds. But, have you ever seen a grizzly run? You're not going to get more than two or three shots off at the most. And, unless you're experienced, you will likely miss the first shot because of the way they charge you with their head down. I think I'll stick to the 44 rem mag revolver for a grizzly sidearm.
It's not the number of rounds that has made it popular, it's the ammo. There are two schools of thought...Buffalo Bore 220 gr vs Xtreme Penetrator 140 gr. I have my Lab with me, and she's always on red alert, so I'll have plenty of warning. I'd rather have 15 rounds and not need all of them vs having five or six rounds and needing more.