I was wondering if the grip on the Glock 30 is the same width as the Glock 21?  Or is the G30 smaller than the G21?  The grip on the G21 is wide for me to get a good grip, which is the primary reason I went with a Para-Ord since I wanted a double stack 45.  Thanks in advance.

The width of the G21 and the G30 is the same, however, somehow my grip on the G30 with a Jentra plug and Scherer extensions is always right on and it feels more like the G19/23 in my hands.

You will have to try for yourself to see how it will work for you, I bought my G30 used from a guy that said it was too small. When I met him, I knew why, he was about 7 feet tall!
Fits me at 6'1" pretty well.

Edit: I wanted to add, that the shorter grip and the curved extension helps me to acquire and keep a higher and consistent hold of the gun.