So I checked out the calc listed above - it's actually the same as on Neu's site. I wanted to look at motors already being used on this plane, so I compared the Neu 1912/2.5Y to the Scorpion 4025-16, both on 8S - the numbers are really close!! The motors are nearly identical in size, weight, and kV. A 17x10 on the Scorpion and a 17x12 on the Neu posts very similar results, with the Neu giving slightly more thrust, a little more speed, and less overall power/efficiency. Or you can put an 18x10 on the Neu and have slightly less thrust, speed, and power, again a little less efficient.

So, looks like the New and the Scorpion are really similar, with the Scorpion just favoring in efficiency and power and the Neu favoring a larger prop. One would think that this would translate to the larger 10S motors similarly, so maybe a 19x10 on the Neu and an 18x10 on the Scorpion. So, an extra $100 for an extra inch on the prop?? Probably not here.

I've heard inrunners and outrunners compared similarly to 2 and 4 stroke wet fuel engines. I think I remember hearing that the inrunners were more like the 4S, which is what I saw with the calculator. So, maybe a little stronger pullout and better throttle response from the Neu?