Dual channel! I don’t think there is a lot to be gained from going to interleaved sampling to get 2 MS/s on one channel. 1 MS/s is plenty to cover basic audio-frequency use and 2 MS/s isn’t going to suddenly make it suitable for high speed logic or RF.
What I would love to see is 2 input channels plus a function generator output. That way I could apply a test waveform to a circuit and compare the output. Ideally there would be a built-in sin / square / triangle generator plus the ability to load a arbitrary waveform from flash. I now use my laptop sound card as a function generator. That works fine, but the maximum frequency is limited. Also, since the nano is single channel only I can’t display both the test waveform and the output.
I know the enclosure is part of keeping it cheap, but I am not thrilled with the d-pad control. I very frequently hit left/right when I mean to hit up/down or vice versa. A set of more standard “soft buttons” on the right side of the screen plus value up-down controls would be a big improvement. If that is possible within the target price range I would buy a second one.