RE: Prop Size for Avistar with TT. 46
Use which ever one you have -- there isn't a troublesome difference, like there would be if you used an 11-7 (too much prop) or a 10-6 (not enough prop).
I use 11-6s for general flying with my two Superstar hot rods (on wheels, or floats) but an 11-5 will work as well -- I just like the extra bit of speed.