I have one and like it very much. It's not a pure Shadows echo in the sense of timings and levels of heads. However it is possible to do very good Shadows sound in a live enviroment situation. It can do the Roland style echos very well. The quality of the echos are very good and the unit well made. I tried it at our club a few weeks ago and people thought it sound very good.
For a quality tape echo unit that sounds like a real tape multi head unit it excels, just not absolutely perfect for some Shadows but not bad either.
If you have an understanding of MIDI you can control parameters like head levels more accurately than say the default interface of either full or half head volume level. Some Shadows echos of the Echomatic have up to 6 heads, but some use 4 heads such as the echomatic 2 . This unit is reasonable at mimicking the em2 type of sounds particularly and the Binson and Roland machines HBM used.