The problem with the quad is that when you are only seeing an decent representation of the waveform you are supposed to see at about 1MHz or less, this is a great limitation to the usefulness of the device. The nano seems to have about the same useful bandwidth, I bought the quad hoping it would be a big improvement over the cheaper nano, it was not. Neither of these devices suit my needs. The wave out on the quad goes up to 8MHz in square wave mode, so out of the box, as is, you would expect it to perform like a good scope should up to at least 8MHz. Sadly, this is not the case. I think the reason why there are no more application or firmware updates to this project is that developers already understand their efforts are better used elsewhere. I wish the merchants selling these (including seeedstudio) would advertise upfront in bold type the 1MHz or less bandwidth limitation so people are tempted into thinking as I had that this might actually be a useful tool for their >1MHz applications.