From a test point of view REV A devices do seem to have enhanced download speeds as well as the obvious upload increase.
I am currently on leave in Nelson, i have my OKTA Touch in USB modem mode with an inductive pad off a Wilson signal boost amp. I am getting 1200kbps solid and i am just around the hill from the site, -59dbi signal strength with the booster on. With out it fluctuates between 370 and 1000kbps.
When i tested the Aircard 595u REV A card with the booster my speeds where between 1600 & 1800kbps stable.
So the REV A devices have better performance across the board.
Note i am trialing a new mini portable YAGI with my booster kit next week. I am betting i can get the speeds on both OKTA TOUCH and REV A Card up even more. Has been the case else where with a fixed YAGI.
As i side note you can view field test data on the OKTAs and in the HDR mode you can see what max speed you will get, by small shifts in antenna or phone location or directional shift on a yagi you can increase max speed considerably.