Jobo ATL-1500. Really great results, mostly due to consistent temps, times, and agitation (guess that covers it!) which I could never get doing it by hand. Crucial for T-max and Delta films especially.
I find that I have to reduce Kodak's published
rotary processing times by another 10% or so. I use a presoak of 5 minutes (jobo's recommendation to improve evenness of development; not necessarily to Kodak's or Ilford's liking
), and that likely swells the gelatin enough to allow the developer "in" more. Since I scan my negatives (ducking head to avoid Wrath of Analog Gods here) I want them on the thin side--if you're printing conventionally this may not apply to you.
Best thing is, I have done hundreds of rolls, so I have a good idea how the setup will behave. I can usually nail the proper development time for a new film type after the first roll, and even that one is usually printable.