I have the ATL-1500. If you've never used a Jobo, you are in for a treat. I have never enjoyed the tedium of filling, agitating, and emptying hand tanks while watching the clock, and the set-and-forget operation of the Jobo is fantastic.
As long as you use enough stock solution (no matter how you dilute it) for each roll of film, you should be OK, as long as the total volume of dilute developer does not exceed the tank's capacity. I use Xtol or Mytol, and I use at least 100 mL of stock solution for each 35mm or 120 roll. For three rolls, then, at 1+1, I need about 600 mL of diluted developer, which is no problem in the large tank. I have no experience with Microdol nor recently with HC-110 so I don't know what the minimum volumes are for those developers though I'm sure Kodak's website does!
Film makers differ on whether a prewash is needed, but Jobo recommends it for best results and I've always done it; the machine has it programmed in though you can deprogram this if you want to. I have never had a problem with uneven development even with dev times of 3:30 or so.
Good luck, let us know how it goes.