What is the reason you want feedback on the 6400 Vl2007.
I'm running the 7900 on a weekly basis with a 19 or 28 inch bar. I really love that saw. I bought that model saw because it's the most powerful saw in it's weight range. This advantage point is not valid for the 6400. The 6400 is 300 grams lighter but it also has more than one hp less power.