I received my 20MHz version - was only 20 bucks extra, just in case I don't feel like hacking the software. I am planning to add LAN port and maybe the counter and have already ordered parts. The unit did not work out of the box though! Fan turns on but not the screen. I opened it up and fiddled with wiring and then it started working, only to stop when I put the case back on. Finally I left it without case in order to play with it.
This thing feels and looks like a toy. The quality of the plastic is way below my Rigol stuff and the metal chassis inside is like that Siglent, not quite as much rust but it's really nasty and dirty and full of smudges. I was expecting that, though, having seen pictures here. The user interface is, however, quite nice and intuitive, at least for basic waveforms. The frequency of the oscillator was 1Hz off at 10MHz and kept stable, if I was to trust my HP counter which isn't calibrated. It also stayed stable over time. Using external 10MHz input did not make any difference in the precision of the output waveform frequency at 1kHz. What I was impressed with is the quality of the sine wave - I measured THD of -85.3dB on channel 1 and 2dB worse on channel 2 with my Keithley 2015THD, with 10 harmonics. That is a spectacular result for something like this, isn't it?
I'd say this thing is a better option than any of those simple classic function generators. User interface is nice and performance seems good. It seems upgrading from 20 to 100MHz would not get me much in practice based on what people are saying about the drop in signal quality and limitations of the non-sine functions which in most cases are already reached in the 20Mhz "model". Not sure I'd bother to upgrade bandwidth but I will mess with LAN for sure.