HC-110, mostly with HP5+.
Like you, I wanted to avoid mixing powders. In addition, I wanted to avoid fussing with a lot of temperature control. I process in a Jobo drum w/o bath, and can't guarantee that the drum temperature stays the same as the water temperature. My "darkroom" temperatures range from 68F to 74F during the year. According to http://www.covingtoninnovations.com/hc110/ development time can be adjusted to temperature by the formula:
New time = Old time × exp(-0.045 × (New temp °F - Old temp °F))
- Water (bottled distilled) and Jobo drum at room temperature
- HC-110 dilution H
- Adjust time according to www.covingtoninnovations.com/hc110
- Develop/fix/rinse on a unidirectional Beseler motor base
Dilution H gives me reasonable times in the drum (8-12 minutes, depending on temp) so I don't worry about the time spent filling or emptying. HC-110 is used dilution H as a one-shot developer.
Not quite as casual as Jim Galli, but no fuss, minimal equipment, reproducible.