I actually swap between the ddm tuning 35watt ballast and the 55watt Morimoto ones from TRS. Although one of my ddm tuning set already died on me the second set has been trouble free.
My morimoto ones have been having flickering issues since day 1 and i am about to swap out one last part that they suggested to see if it will fix the issue. One thing i do have to say is that the going from 35-55watt there is a HUGE difference. Its actually too bright and i get flashed by other drivers now. I'm running 5000K morimoto bulbs which matches the oem rings perfectly but i am going to switch the out and try out the 3000K yellows for two reasons. 1. it should be less blinding for others and 2. the yellow should provide more contrast on the road. I use these to mainly help me spot out those humungous potholes we have here in NY (BQE) and the super bright 5000k lights sorta just washes everything out in bright white light.
In my opinion so far....the DDM 35watt ballast paired with the morimoto 5000K bulbs looks the best. No need to go 55watt nor spend the extra dime on the morimoto ballast. The ddm's are cheap enough that you can have 2 sets as back up before it would cost the same as the morimotos.