Lol, I have been wrong a number of times, so don't think I'm infallible.
Don't get me wrong, I'm not suggesting that you sell the A123s and get lipos because the M1 cells ARE nice. It's just that those cells get a little heavy once you get to the high cell counts.
If you decide you want really high speeds, ballooning can be as high as 0.5" to 1" depending on the tire. You plug that into the calc and watch the top speed get up there fast!