Thanks again for the replies and suggestions. I had an opportunity to try the Digitech CF-7 Chorus Factory the other day-after discovering that it has an emulation of the Boss CE-5 (which has done very well in the poll, even though it was originally intended as a gu*tar pedal!).
The music shop in question wasn't equipped with particularly good instruments or amplification, but I could at least hear that the pedal was pretty versatile. The only problem was I perceived a small delay between switching the pedal on and off. It wasn't a very long delay, but the drop-out of volume was enough to bug me. I have a Digitech Bass Synth Wah pedal and have had many other of their X-Series pedals and none have ever had this strange delay.....
Maybe it was just a duff pedal or because it was running from battery power....?
Anyway, I'm still very undecided! Many of the replies suggest pedals larger than the standard Boss/Digitech dimensions -so unfortunately they won't work for me. Also, with regards to budget, I'm prepared to spend a reasonable sum but not like TC Electronics or AnalogMan prices....(the latter wouldn't have enough controls anyway-see my 1st post regarding why I didn't like my EBS UniChorus).
Thanks as ever guys!