I've only put around 1k rounds through a P-07 and have well over 10k through a P-09. I own two P-09's, one set up with a red dot and one with open sights.
1. All three pistols are excellent mechanically, as far as the barrel lock up and slide fit. I have demonstrated with many videos how well each gun can be shot at 25/50/100 yards and at 200 yards for the P-09. I don't own and have not shot anything that provides higher accuracy than the P-09, including one very expensive SIG X5.
2. Ergonomically, the P-09 and P-07 are identical from a grip and trigger reach standpoint. The grip sides are too flat and the reach is too short for me for a competition gun, but I have addressed that on each one with some epoxy and/or Sugru. This is a personal need, not necessary for most shooters, and it not a criticism at all.
3. The pistols are light, but pose minimal recoil control challenges, I suppose due to the high grip and low bore axis plus longer lock time than on most guns. They are very controllable in 9mm for their weight.
4. Now for the differences. The P-09 is a full size gun, excellent for a range or house gun, but not for concealed carry, at least for me. The P-07 is MUCH more concealable, without feeling like you are holding it with two fingers. To me, the P-07 is about as large a pistol as I would consider for a concealed carry gun. For that purpose, it has advantages over the P-09.
5. I have not open-carried a handgun. I'm not an LEO or military person. I assume the P-09 would work great for an open carry gun where the size wasn't a disadvantage. I would think the P-07 would be more comfortable while driving, but I don't know.
6. Accuracy for a defensive gun--Both are "accurate". I like the additional weight and longer sight radius of the P-09 over the P-07. But I like the weight and the sight radius of a 97 over a 75B or P-09. I don't like carrying a loaded 97 around at all. There are compromises--weight and size versus sight radius and recoil control.
7. I can shoot a P-07 just fine. The small size gun does not have a mechanical accuracy disadvantage at defensive distances, if one has time to aim the gun between shots, in my opinion. This was my biggest concern when I first considered buying a P-07 after three years with the P-09. Could the P-07 even come close to being as good a shooter as the P-09??? The answer for me, after shooting the P-07 in exactly the same scenarios as the P-09 (except at 200 yards), is that the accuracy is excellent, only the weight and sight radius are reduced. The mechanical design of the P-07, combined with some exceptional manufacturing tolerances, can provide exceptional accuracy, just like the P-09.
8. The P-07 is, to me, a "P09 Lite". And it doesn't get any better than that.
Joe