Not tried the 4 stroke, but a friend has the OB1 500, decent little amp, has a nice bit of built in fuzz and the footpedal switch between the two is pretty neat. However it can't begin to compare to my AD200b in terms of volume, tone and warmth
£70 wesley MM copy. After that I bought a Vintage V940a, was pretty good for £200. Kept it for 8 years, then sold it and bought a 5 string Warwick Streamer LX which I still use today!