I don't include preflop, because PFR gives a good feel for preflop aggression. This is probably the most important stat (yes, ahead of PFR and VP$IP) because it tells you how they will bet a hand postflop. If someone with PFA > 3.5 is putting me all-in, I'm far more likely to call than someone wiht PFA of 1.0 (1.0 means their all-in=nuts).

People with low postflop aggression and high VP$IP are generally calling stations, I like to sit to their left to get paid off.