Re: Baby Glocks
I carry either a G27 or G29 in VM2 holsters. I like the G27 for it being lighter sometimes, better with lighter clothing, but the G29 hides very well too. I tend to wear it more with long pants and jackets, thought that isn't necessary I suppose.
As for controllability, I've heard a little 16yo girl and also my wife who is recoil sensitive, both say the G29 with fairly stiff 180 or 200gr. loads is preferable to the G27 with stiff 155's, or worse, 135gr. Corbon loads. The G29's recoil is a "shove" with heavy bullets, whereas the G27 is more "snappy". I'd say from strictly a controllability viewpoint, the G29 with heavier loads, say 180 Gold Dots? Loaded to about 1150fps from a G29, that gives good results all around.
The G29 being wider to grip helps, but you'll definitely want those pinkie extensions for the small capacity carry mag. It doesn't add much length and no capacity, but adds a LOT of support when firing. I use plain G20 or G22 mags for spares, which sounds like what you want to do.
I have a G21, but don't own a G30. I just sort of stopped when I found 10mm, such a fun cartridge to shoot --if you load. Either one would be a fine carry rig, but I'd only go with the G29 if you plan on loading for it. 10mm is costly stuff if you don't load.