Lookout v2

I don't know, if you see the hip joint as the pivot point, then 5mm variance in crank length vs the variance of 100mm in Femur length seems trivial for different rider lengths. The taller guy would normally also have longer feet, that displaces his ancle joint (the other pivot) further away from the pedal center point.

I would also be tempted to buy a 29er if I had the extra cash or could convince the Swambo to rearange our budget to suit. I think the math is simple. Pi(3.142) x (29-26) = ~9 inches per wheel rotation further for the same gear ratio and cadence between the 29 and 26. Ok the 29 is a bigger wheel (lever to get moving) but that can be offset by using longer cranks. Also if your tall your longer upper leg facilitates a longer lever to turn those cranks compared to my short legs. So except for manuverability of the 26er, the 29 will beat you over distance.