OK, I'm going to put my 2 cents in here. I don't really see much point in using Microdol-X any more. Film grain is not nearly what it was when this developer was the thing to use. Used full strength, you loose about 1 stop of film speed. At EI 200, you are getting mighty close to the speed of Plus-X (125) and the results will not be nearly as nice. You loose some sharpness as well, and the grain that shows is a bit mushed up. Dilute Microdol-X 1+3 and you gain back film speed, but you loose the fine grain effect.
D-76 (ID-11 for you Ilford fans,) on the other hand can give you full film speed when used either full strength or diluted 1+1. The usual effects are present. Finer grain (not as fine as full strength Microdol-X) is to be had with the undiluted stock solution. Grain goes up a tiny bit if you dilute it 1+1.
Best of the bunch for normal processing is XTOL for me. You can have your cake and eat it too with this brew. Grain is less apparent than with D-76, images are a little sharper, and you get a mild speed boost when used either full strength or diluted.
If push processing is your thing, then try some Diafine. Being a two part developer, it works very well for images exposed under contrasty, but low, light and gives a real speed boost up to about EI 1250 or 1600. It does not work well for normally exposed Tri-X.