I have both of those. The Pono is a little better built (shocking given the higher price, right?), but has a fatter neck, no taper to it whereas the Ohana thins slightly towards the headstock. The Pono also has slightly wider string spacing than what is noted on the HMS website (45mm at the saddle vs. 41.5mm spec, and that's one from a recent batch). As many have mentioned before, the Pono seems a bit on the quieter side (still has stock Alohi strings).
Another comparable all-solid to consider is the Kala SMHC. I have one of those as well, to be donated to a charity auction. The build is more like the Ohana (again, no surprise given the similar price), with a fatter neck. It's the heaviest of the bunch and is the only one with closed back tuners. Sound was slightly better out of the box and the finish is open pore. The body shape of Kalas is slightly different, a bit wider lower bout.