I own one of those, for the money (sub £200 in the UK) they are not too bad, in fact I am quite happy with it. I have a nice Tek analogue scope but needed the ability to do single shot triggers sometime ago...
That said, there is far better out there these days. The 50 MHz Rigol is not much more money, and beats the Owon (and the new revision) on pretty much every front (sampling rate, bandwidth & memory which are the most important things with a Digital Scope).
It is a shame the bandwidth of the Digilent analog discovery is so limited (5 MHz), given the 100 MSp/s 14 bit ADC, or I would recommend one of those...