I don't use Microdol, but have used Ilford Perceptol. I'VE BEEN TOLD THE TWO ARE ABOUT THE SAME! I always use it at 1:3 and really like the rersults with everything from Fuji Acros to HP5+, but I never rate my film at box speed when I use it. Tri-X would be ISO160 or no higher than ISO200. That's for me and a condenser light source. PanF+ is really, really nice in Perceptol also, but again you have to cut your speed in about half. Ilford DD-X works perfect with Tri-X at 1:7 and the speed is right on the box. That being said, I've been using Xtol replenished for all my film as of late and have no complaints at all. So many good things out there yet, so just pick it and work with it 'til ya get what ya like. Still fun at 62!