I have the ATL-1500 and use it regularly. I have tried standard black & white processes, C-41 and E-6, and it works great every time. I don't have a sophisticated water supply with balanced temperature, so I use the 12V pump option and pump water from a plastic basin where I regulate the water temperature myself. Even so it is fairly automatic, as only the developer stage need precise water temperature for rinsing and so on. The internal water bath in the processor takes care of heating the chemicals to the right temperature. So it is mainly a matter of selecting the right program, mixing the right chemicals and pouring them into the right container beforehand, adjusting the temperature in the separate plastic basin and push the start button.
I have the ATL-1500, which only differs from the ATL-1000 on a few minor points. For example, it is possible to make changes to the different programs.
When not in use, the lids on the six chemical bottles should be left open because of the rubber sealing rings, but before starting a development process all lids must be closed.
I like it a lot, and the results are great. I would hang on to the 1000 and perhaps keep the 800 for parts.
The drums can be quite expensive. I have several 2513 drums for one 35mm film, several 2523 drums for two 35mm films (two spools) or two 120 films (two films on one spool) and finally one 4219 drum for up to five 35mm films or six 120 films.
Jobo has chlorine-free "Processor Clean" for removing deposits and residues, but it is cheaper to use citric acid in granulate form (dissolved in warm water), because that's what it is. Cleaning between different processes is highly recommended.