Mine is well and truly from the past. It's a mid sixties WEM Custom Copicat. I bought it secondhand not long after I got my Rickenbacker. It still works well. ( I have another older model as well, but that's got problems.)
I picked it up for a song at a junk shop, - the proprietor didn't know what it was - he said he thought it was some sort of strange tape recorder but didn't know how it worked.
I tried various other solid state types over the years, but kept coming back to the Watkins. It's hard to explain, but for me it just had "that" sound. One thing that I did notice, was that the solid state types were too precise, if that makes any sense.
There was always that hint of wow and flutter in the Watkins delays, seemed more natural to me. Plus the fact that it was valve driven, - had a very warm tone. The echo and delay adjustments were seamless, and the depth control was excellent.
I also found it to be a very useful preamp, - switching off the delay and cranking up the gain until it was overdriving. Produced a beautiful fat dirty sound. Running that through a Roland PA250 and into a pair of 150W Peavey Mk111 boxes, I could rattle every window for two blocks.
We used to play a lot of instrumentals using it, some of which were Shadows plus various others. - Apache, Walk Don't Run, FBI, The Boys, Bombora, White Rabbit, Pipeline, Albatross, Wheels, Joey's Theme, to name a few that I can think of.
Main drawback was maintenance, periodically replacing the tape, cleaning the heads, lubricating the rollers. Another was having to remember the exact settings for each tune. Tape noise was a minor annoyance. I used it continuously for almost 20 years without any problems. Great little piece of gear and testament to Mr Watkins' very clever engineering.skills.
Vic