I have an R36S, it also has dual TF card slots. But the R36S is shaped like a small DMG GameBoy, and it is really uncomfortable to hold. All your fingers get squished together, so actually playing games on it can be frustrating at times.
The device itself is pretty cool, playing up to certain Dreamcast games very smoothly. And for $40 USD, thats a really good price. I want to know the dimensions of the R36H, because if they can fit in a pocket then they've just killed the R36S.
Also, the R36S comes with two of its face buttons internally connected to each other which makes pressing them feel really really bad. Popping the device open and cutting the plastic link between the buttons provides and immediate increase in usability. I wonder if this issue is fixed or is carried over, as it appears to use the same plastic buttons.