I have been using staining developers of various sorts for over 10 years. PMK is my standard--it is reliable, keeps for a very long time, and I have my times figured out for every film I currently use. I have used ABC in the past with excellent results, but only with Tri-X sheet film in 8x10. I know that Gordon Hutchings has said that PMK negs should look a little thin, but I have gravitated toward very full development of all my negatives. This way I can use them for both historical processes and standard silver-gelatin printing.
I'd like to put in a plug for Pyrocat-HD. I did some cost comparisons 3 years ago and found that Pyrocat-HD is the cheapest developer you can use, costing about half as much as PMK per liter of working solution. The results are hard to distinguish from PMK, when printing on VC papers. With graded papers, a Pyrocat neg will require less exposure than an equivalent PMK neg. Its only failing is that it does not have good keeping qualities compared to PMK, so you have to mix smaller quantities more often.
I friend of mine formulated a metol/glycin/pyrocatechin developer similar to DiXactol, and he swears by it, claiming finer grain and beautiful gradation. But when I tried it the results were not nearly as good as I get with PMK. In my opinion, DiXactol is over-priced. The components are quite cheap, so you are paying a premium for the "secret" formula.