Hi Paul,
I've had a lot of trouble with the Deepressor and eventually gave up and exchanged it for a Carl Martin Classic Opto comp. The Deepressor left the upper registers more intact than the Carl Martin,
but it had a bit more roll-off on the lows. The input PAD button is effective but takes away quite a bit of harmonics and dulls the highs. I was hoping it would really "growl" when set to high compression settings, as advertised by the designer, but it must be very subtle because I never noticed it. It does deliver loads of sustain though, if that's what you need, and without adding too much noise as well.
My biggest problem with this compressor was that it had a tendency to hum like crazy, especially when used in combination with other pedals. I was surprised when i found the shoddy soldering inside the unit when i opened it up to see if anything was amiss inside. The ground wire had come loose from the print circuit; it looked like it had been glued in place instead of properly soldered. Instead of sending it back for repairs i fixed this myself, but it did not solve the humming problem.
I tried every trick in the books to fix this problem, but I never succeeded, and eventually ordered a replacement under warranty. Then I found that the replacement unit had exactly the same problem. I contacted Palmer about this issue and they never bothered to answer. Then I decided I had wasted enough time, shipped the Palmer back and got the CM.
The design of the housing seems so neat with the screw holes but if you tighten the screws the pedal lifts up at the front. I ended up making a construction so I could screw it down at the front as well. Access to the input/output jack sockets is hindered by the encasing; when using angled jacks you'll have trouble arranging your patch cables neatly. The input PAD button is located in an awkward place when everything is cabled up on your board, so switching if on or off during sessions is not so convenient.
For me, this experience made me weary of buying another of Palmer's products. Too bad because they recently introduced an octaver pedal for bass and i am interested to find out how well it performs.