You can buy two P07's the same day from the same shop.
Chances are, one will be more accurate than the other and one will run longer without breaking than the other. They are machines, like cars, lawn mowers, refrigerators, etc.
I carry a P07. It's accurate, reliable, feels good in my hand, etc. The P09 is all of those + bigger. Longer, taller, heavier. Longer is not so much an issue as "taller". Taller means the pistol grip/magazine stick out more towards the rear (I wear it IWB at about 3 to 4 o'clock) and is harder to hide under a loose shirt/jacket than the shorter P07.
Is my P09 "more accurate" than my P07? I'd have to say it is - barely.
I also carry a P01 Omega at certain times and I like it. But the P07 is #1 for me.