Don, Let me say up front I'm going to give you a completely biased answer! I use mostly T-MAX 100 (TMX) and couldn't control the highlights. They tend to burn out with this film. I also shoot some Plus-X, and a roll of T-MAX 400 (TMY) & Tri-X now and then. My previous favorite developer was HC-110. Though Plus-X in D-76 1:1 is loved by many, I found it lifeless. Developed in full strength, it's OK. XTOL brought the TMX highlights under control, without losing the tonal qualities everywhere else. It works just as well with the other films I've listed. I just got the 1999 Kodak Professional Photo Catalog, and it has a chart on page 19R comparing 6 developers. I'll try to summarize it. They rated shadow detail, grain, and sharpness. If you number their chart from 1 to 10, with 10 being a lot, fine, and sharp, respectively, the results were: T-Max 10, 2, 7 Xtol 8, 7,10 D-76 7, 3, 9 Duraflo RT 7, 2, 9 HC-110 5, 5, 7 Microdol-X 2, 9, 1(posted 9068 days ago)If that's confusing, best get the catalog. At any rate, Xtol is the clear winner in most areas and is beat by only a slight amount in shadow detail by T-Max and grain by Microdol. The grain advantage of Microdol seems completely wasted, as the sharpness is the worst of the group.
I usually use Xtol 1:1, but haven't found much difference in tonal quality. I just do it to save a bit on developer. There is extensive data for Xtol on the Kodak web site- highly recommended before using the stuff! Good luck.