the printo is a great little machine for a small darkroom...I got one at home that I use for b&w mostly. any RA4 processor can run b/w as well--and the Printo does a good job of it. Takes very little chemistry and can be regeared easily for about 4 other speeds, and you can adjuist the temps in each tank as well as add on other tanks & energy therm/motors. It's a neat little machine--don't think of it as a "big" processor. It's not, it's like a hobby version of the larger lab machines, but you could easily make hundreds of prints a week with one. if you make alot of b/w prints, and want to do some RA4 on the side, it would be a good machine to use for it. as an added bonus to the speed & convenience? You keep your hands dry....

but for the original question? The only way you can "crank" out any kind of print--color or b/w--is with a roller transport processor. It's possible to make alot of prints with trays, but the ease of the processor will become apparent the minute you use one. Even a little machine like the Printo can run circles around a trayline and drums are no comparison....

The Printo is a good deal used because it's still being made & parts are available....

btw--the size of the basic machine (2 tanks and entry module) is about that of a 20x24 tray...the wash tanks and dryer add more space, but the basic Printo is very compact. Not as much as a Fujimoto, but it's not even as big really as a DuoLab (which would be another option or a slot processor).