Since posting in this thread earlier I pulled out the Marin and tried reworking the front end to eliminate some of the lifting going uphill. After a test ride today with a longer stem and moving the new seat forward a bit (after the photo was taken) it does better. Had a lot of fun riding and even managed a full somersault endo trying to stop on a steep downhill section (rookie move). The bomber fork takes the jolt out of rocks and roots enough to not try to avoid them.