Believe it or not Overkill is my very first hobby grade rc ever. What little bit i know is because of this site mainly Jimmie Neutron correcting me when i'm wrong. That and lots of reading and research when i see something that interest me. Before i started on Overkill i spent every night for 2 months looking up parts and putting it together in my head.
As far as your diff servo is there any way you could make a video of it working and post on here?