T-Max developer is "best" for this film, in a purely technical sense. They are made for each other to accentuate and complement each others' characteristics. If results aren't great, it is not the fault of the developer. It is likely the result of other things, such as using T-Max film in a situation to which it is not suited, metering technique, EI differences person to person, and general lack of testing of your film and developer. It could be that you just don't like T-Max 400. I like it as a "special-purpose" film, but not as a general-purpose film. Instead of flailing around searching for a magic developer, I'd stick with what you are using and spend some time doing some really serious testing of your materials. The way I look at it, when you can reliably predict/control your negative densities with what you have, then try judging the developer and comparing it to other ones.
