From your question, I am thinking that you don't want to remove the look of grain in Tri-X; rather you want to "master" it. I couldn't agree more. To me, the main reason to use Tri-X, versus other excellent iso 400 films, like HP5, is the even beauty of it grain. Rodinal brings this out strongly—eg gsgary's spaniel. On the other end of the spectrum, Microdol covers the grain, at the expense of acuity. It's a matter of balance. I like Xtol, with gentle, five-second agitation every 30 seconds but I have tried pretty much everything. Intermittent water baths, split developers, stand development, you name it, I've given it a whirl. (Truthfully, I haven't tried everything. I still want to try caffeinol. I love the look of those images posted on Filmwasters by caffeine addicts.) I do think that technique matters as much as materials. Exposure, temperature and agitation have as much impact on the look of the negatives as chemistry.