Thank you Matt. Environmental and allergy doesn't pertain to me. And I mix up my own Microdol (non X) with ebay metol, sulfite, and kosher salt from the grocery store. I can't tell it from the nice stuff with the yellow packages, in action. I don't get it, but nobody has to answer my post. Just one of those things in life I suppose, where new technology didn't fix a problem that didn't exist. But Xtol has its fans, and I suppose they're not stupid. So there must be some advantage to it.
I can't develop sheet film in a tray with Microdol 1:3. I'd be standing in the dark rocking the tray half the day. Microdol is no good there, and you don't need micro-fine grain on 4x5 anyway. It would be ridiculous to use it for that. But I CAN use exact same 2 ingredients without the salt and have D-23 straight, which is much more reasonable on sheet film than Microdol.
When shooting hand held Xtol is amazing, because it gives you probably a stop or more shadow speed. That's the cool thing about Xtol, it yields some of the highest shadow speed of any developer, yet gives up nothing in terms of grain, sharpness, or tonality. A stop extra makes a big difference in those circumstances.
Mixing your own developer is really neat, it gives you the freedom to always mix just the amount you need, and you're in control regarding the ingredients, and can tweak the formula at will. That freedom is nice. I used Xtol so that I didn't have to mix my own, though. And Xtol was the developer that met all of my needs, particularly when using it with T-grain emulsions like TMax 400, with which it has a very symbiotic relationship, but it gives great results with any film, and using it replenished like I did yielded good economy too, where I'd get about 70 rolls worth from a 5 liter package.
I have tried Microdol-X a few times, but I probably didn't learn it well enough to be a good judge of whether it was to my liking or not. I realize it's not the same as Microdol, which I have never used, but the results with Microdol-X were, to me, disappointing. I really missed the sharpness the Xtol negs provided, particularly when making larger prints from small negatives, like 16x20 from 35mm. But I didn't use enough of it to really be a good judge, so I should probably withhold my opinion; I only processed 20 or so rolls in it.
I think it's a matter of finding something we like and work with it. Kodak were probably trying to make a new product that would seem revolutionary. Maybe it wasn't revolutionary, but stuff like that keeps people's interest going, and Kodak can sell Xtol to those who believe in it, and make no money at all from someone who mixes Microdol from scratch.

Since they still sell it, and people are talking about it, getting others to try it out, it must be doing something for them that makes it worthwhile.
To me it's the best all-round developer out there.