@Laz, I've got a copy of your son. Mine is also a 10-y.o, 95 lbs, running deep 34 mph at 15 off. He's currently on an old D3 RC 63". I'm considering a Mapple 64.5 for next year, but it seems to be hard to get multiple advice on sizes. I'm not sure how much a kid at this age can give good feedback when trying different skis... He has tried my 66" skis and skied close to PB on them on the first set, but those skis are a bit too big for him anyway.