Reliability?
My G19 has been more reliable out of the box than my CZ P-01. However, the P-01 has only had FTF on some really crappy "NATO" 124gr ADCOM FMJ. Most times, the failure consists of the cartridge stuck halfway in the chamber. Forward assist gets it in the rest of the way. With better ammo and/or more attention to maintenance, there are no issues. This is compared directly to the G19, which has eaten 1500+ rounds of this ADCOM stuff like candy.
Recoil?
My impression is that there is more upward muzzle flip with the CZ compared to the G19. Just enough to be different, not enough to make much of a difference shot to shot.
Size compared to Glock 19?
Darned near the same. I had the G19 first, and the CZ fits in the same holsters, albeit a bit tightly.
I'd have a hard time letting either of them go. I really like the CZ, but the G19 gets more use.
jm