thisisdenny Is Correct...
Correct me if I'm wrong but I think the glock 33 round magazines already have the +2 floorplates to reach the 33round capacity, with a regular floorplate they'd actually be 31 round magazines.
You're right! We own two of these magazines, and they work flawlessly in our G17 and G19.
Keep in mind, the G17's wild cousin is the G18--a full-auto select 9 mm!
With regard to your gun choice, I'd start (even though
I didn't) with the 9 mm.
My G17 has about 11,000 rounds on it, without one hiccup. I've not replaced a broken part, nor effected a repair of any kind. In fact, all three of our Glocks, G17, G19 & G21 have proved to be exemplary guns, over thousands of rounds fired from each. None have had any broken components replaced, or repairs made.
I started with a Glock, so I've learned to shoot them well... The G21 was actually my first purchase, back in October, 2005. I love that gun, and I put over 10,000 rounds through it! That Christmas I added a G19 for Judy, and I have to tell you, that's a sweetheart of a 9 mm! As ammo prices soared, I added a G17 as a dedicated range gun for me, and it paid for itself in a year, on ammo the savings alone. Think about that last part...
IMO, the 9 mm is every bit as much fun to shoot as the .45 ACP. Loaded with modern self-defense ammo, it's plenty effective against the two legged beast.
The advice to try and rent both guns was sound! I rented or borrowed all of the above-mentioned guns, putting at least 200-rounds through each, before deciding. I also rented a G22, G31C, and several revolvers. I enjoyed them all. One night, I was handed a MAC-10 full auto, chambered in .45 ACP, and told to "Have at it!" Now
that's fun!
I was given the opportunity to fire two of the XDs, on two occasions--a .40 S&W and .45 ACP. I have to say, they're nice guns! The grip and palm swells do feel good. But they sit tall in the hand, the way a Beretta does, where the Glock's bore axis rides real low in the hand--and I just like that better!
You know, the way this usually works out, I can easily see you owning both! A 9 mm range gun and .45 ACP bedside gun makes perfect sense to me! What's more, if one's ever out for mods or service, you'll still want a gun in the house, yes?
--Ray