Big, important, subjective question:
1. Carry: The P07 is about as easy to conceal as the G19, with the small addition of a beavertail (which may impede groin holstering while sitting / sneezing). Weight difference is negligible. P07 has a slimmer arsepart (grip), which is nice.
2. Safety: this is dependent mainly on the user. I was squeamish about carrying a G19 with a round in the chamber, but have no problem doing so with the P07 with the hammer down. The manual safety of the P07 is a PITA, but the decocker is fine. Neither will fire if you don't pull the trigger.
3. Mags: I never encountered problems with FML Glock magazines, but my P07 magazines frequently fail to drop. Glock has more aftermarket options.
4. Shooting: the P07 has an excellent frame design. For competition shooting, the trigger reset is longer than the Glock's, which takes getting used to. In my hand, ergonomics are superior to the G19 in every way. The G17 wins on sight radius and feel. Yesterday I shot an old 2nd generation G17 with a very nice 3.5# trigger in a couple of IPSC stages, and felt it to be totally superior to my P07 in the same scenario. For self defense shooting, this is not as important. The P07 is comparable to the G17 in sight picture recovery time, i.e. is well balanced for a light pistol. Most new Glock triggers are inferior to the P07's in single action for first pull.
5. Aftermarket / accessories. Glock wins hands down. Finding nice accessories for the P07 is often a baffling ordeal, especially for southpaw shooters.
6. Reliability and durability. For normal gun owners who do not intentionally neglect and abuse their guns, both a P07 or 9mm Glock should outlast the shooter and fire every time.