Still running old Karhu BC 100 skis with dynafit TLT 6 boots and dynafit bindings. It is a light set up that is great for the uphill grind and I am not afraid to take it down groomers.
I wear a 45.5 in both scarpa and Mammut - I have 3 Scarpa shoes / boots and 2 mammut including these. If you already have a boot that compares, I would keep the same size.