I think a curve setting between 3 and 3.5 (5 is default) for the pitch is the best combination between sensitivity at low G flight (straight and level) and when pulling around 4 G's (loops and stuff).
In my opinion a curve setting of 4, like you guys use, is too sensitive when flying loops and barrels. You will have the nose stamping effect when you correct to keep up and that doesn't look nice from outside. The other thing you could do is put the "shift" at 5.5. You will not use the full pitch axis for formation flying anyway. (Of course when you also fly Solo's you probably do use that area). The roll and rudder settings are not that important, but if your interested, I have the roll curve at 2, the D-zone at 0.4 and the shift at 5. For the rudder I have D-zone and shift like the roll and the curve at 2.5.
The other "new" thing what will give you the maximum control possible is the "joyrange" setting. It will be good to set that between 1000 and 3000. Check
this.
I use the X52 and I usually fly the Su-27. The best settings can depend on what joystick you use and on what aircraft you fly.
Last thing, I have no D-zones on the joystick profiler.
I hope this is useful and that you will get the best out of your setup and yourself!
Greetz,
Frazer
TIP: Don't change the settings all the time, give yourself the time to get used to your new settings.