Yes they are good! I use 2 different ones. Both 12x16, one a 2 bath in which I have stop bath and fixer for mono prints. The actual development is done in a dish then the paper is lifted out and into the deep tank. I use it that way, like you, as a space saver.
Once you have experimented with the thermostat you can get them to keep the temperature very accurately. They can take about 90 mins to heat up and stabilise so I have a plug in timer which I set for a couple of hours ahead of when I want to start work. Smaller ones will take less time.
My other one a 3 bath which I use RA4 Kodak Ektacolour developer the middle bath has stop and the 3rd bath is the bleach/fix. When using RA4 the lack of air in the top of the tank when not in use means I can preserve the developer for as much as 12 months and on one occasion 18 months. You must be rigid with your replenishment to get it to last that long. I use the ratio for every 80Sq inches of paper I replenish with 10cc's of developer. I do likewise with the stop and blix.
To preserve the life of the chemicals, after finishing a session, I cover the top of the tanks with a sheet of plastic film of the type intended for kitchen use. If you can get a good airtight seal, when the liquids cool down, they cause a partial vacuum to be formed which means less oxygen to affect the developer.
Mono developer (multigrade) does NOT keep in the deep tanks. One day is it's limit. Tetenal do make a developer, not multigrade type which you can replenish but I found that the tones were somewhat muted.
One word of caution. Ensure that the water jackets are kept topped up. I didn't, and had the heater element burst. They can be replaced easily but at a cost.
Last edited by BMbikerider; 01-05-2013 at 06:51 PM. Click to view previous post history.