It's great. But don't do what I did--connect it to any old power supply. The one I had lying about had the polarity opposite to that of the RH timer. Stupidly I connected it and instantly fried a component. Richard was very helpful, repaired it promptly and sent it back with the RH recommended power supply which I ordered from RH.
The percentage plus and minus D is very useful.
Mike, you will have no problems with reading the quite large display of each step, which can be dimmed as well. I keep mine under the bench because I'm neurotic; I'm assured that it's fine on the bench as regards fogging when tray processing.
Regards - Ross