I have a Glock 34, 17, 19, 26 two 42's and a Just Right Carbine that uses Glock 9mm magazines.
I'd rather have 17 (18 with one in the tube) ANYDAY than 6 of anything else for defensive situations.
That said, I also have a Golck 22 RTF Gen 3 that I have shot the snot out of, now son in law #2...