I have flown with my stock gains which were about 150% across the board. I don't like it so far although it may be the new Graupner props also. It seems very twitchy, a little angry to control when zipping aroung but very smooth in takeoff and hover. It feels funny when tackling high alt wind too but I probably just need to get used to it. I have changed the gains to the defaults listed in the manual and will test them tonight.
Also I found how to recalibrate my DX7s and your DX8. Boot into system settings then change the mode from 1 to 4 or vice versa, reboot, calibrate, then change back again and recalibrate. Removes the need for subtrim now.