I just spoke to Les (Bolly Props) and asked if he could make some carbon props for me. (Two-blade).
I'm thinking of the 13 x 5.5 Pushers. (Approx 9500 RPM on a 60" wingspan, 60 - 70oz plane).
I've tried various carbon props including APC copies and all of them had too much load and I had to boost the RPM WAY too high, which chewed through too much battery.
I have to order 50 of them to make it worth while and was wondering if there would be any interest in this size.
I know the APC props work very well but surely a carbon would be better?   (So long as it was thin).

As far as I know.  
I checked the pitch and that was ok along with the undercamber.
The APC copy actually had a bit less load at the same RPM, but the lap times went from 5.4 to 6.5.
I had to boost the RPM to almost 11000 and then it chewed through the battery.  (Which is already a 3900).

Russel I fly 11x5 3bl and the consumption depends on airfoil which I needed to change. That prop I use was designed for LA 46 where it worked well, and when we tried it on electric, we were surprised how much it takes. Little rework solved all troubles and now it is best prop I ever tried :- ))) ... and believe me, that diameter is enough (at least with active regulation).

If you think you need lower rpm then I do, I know polish guys (namely Kristian if you remember him) make similar 11x6 and if you really think 11" is too small, you can try Hungarian props 12x5 which I hope will test whenever snow will disapear here (yes I saw news that you will like to have little bit of that snow, but you have training from Pazadzhik, so it cannot be too much problem for you :-))) )

however all of them are tractors, we do not use pushers here

my is 65oz ... so you need that 12x5 right? I do not think 70 is too much for that 11x5 prop, you simply set stronger acceleration and it will cover that differnece ... But I am waiting one for testing, so if it comes, I can send it to you, because I can test it only april/may. Here is picture (that is all I have so far) ... it is that my, extended 1" and formed, otherwise all is the same as far as I understood.