If you're going to limit yourself to one Glock, you need to decide what you plan on using it for the majority of the time.
Concealed carry? G26 or G19.
General range usage, open carry, bedroom gun for home defense? G17 or G34, many deputies around here have started carrying G34's as their duty weapon.
Specific range target shooting or a competition class that allows it? G17L
Obviously any one of them could be used for any purpose if that's all you have.
At the moment I have 2 G17's, a G17L, a G19, 2 G20's, a G21, a G23, and a G26.
One G17(Civilian class), the G17L(Competition class), the G21(Heavy Metal class) and the G26(Sub-Compact class) are used primarily for shooting the various classes at GSSF matches. Guns have to be stock in all these classes, no modifications allowed.
With the same shooter shooting the G26, G17, and G17L with the same ammo on the same course of fire, you'll find that the G26 is slower than the G17 which is slower than the G17L.
However, if I CCW one of the Glocks, it's the G19 about 90% of the time because it's a great compromise, the G26 gets the nod the other 10%.
truthtellers said:
Right there I have a Glock 26 when I use standard mags or a Glock 19 with 19 mags.
Why stop there? Use a standard G17 mag in your G26 and you have a short barrel G17 or G34 or G17L, whichever you want to call it, right?
The primary advantage of the G19 over the G26 is the sight radius. The 20% longer sight radius on the G19 (6.49" vs 5.39") makes the G19 much easier and quicker to index on target than the G26.
Unfortunately for the G19, that's also the same reason you'll see very few if any G19's at the matches. They have to shoot in the Civilian or Guardian class against the G17's, and aren't competitive because of their shorter sight radius as compared to the G17. Same reason you'll see Competition class dominated by the G34's and G17L's, even though any Glock is allowed.
GSSF sheet that shows which guns are permitted in which classes is on the last page here:
http://www.gssfonline.com/hot_topics/gssf made simple.pdf
GSSF results are here, it's not hard to compare the times among the same shooters shooting the different guns in various classes and see how much difference the longer sight radius makes:
http://gssfonline.com/match-info.cfm?results=1