Black and White Pull Developers

[elemental]

Around Thanksgiving, I made the "mistake" of shooting a roll of APX400 at 125 at the Met. Turns out I'm not an idiot for making the mistake, I'm an idiot for thinking it was a mistake. With a 25% reduction in development time, these are some of the best APX400 negatives I've produced, at least from a tone/grain standpoint:

I am very pleased with this "accident," and I plan on experimenting with pulling other films in the future. I currently use Clayton F76+, a speed-increasing developer, for all of my processing (which was mostly box speed or an occasional push). These negatives look fine pulled in the F76+, but I'd like to try a developer intended for this sort of thing. Any recommendations? I know Microdol/Perceptol are speed reducers at normal concentration. Are there any others I should know about?

I certainly will miss the low-nastiness of F76+ though. The warnings basically consist of "If you swallow this, be thankful it wasn't Rodinal."