danzyc, I stopped using it because it is very tricky to get the right time and temperature, and I saw no true advantage to using it over other developers out there. I do use Kodak TMAX RS, which is different, and also works with sheet film. TMAX Developer is not recommended by Kodak for sheet film.
TMAX RS is not diluted, and you use full strength each time. You mix 2 bottles from the concentrate. 1 is for use, the other is for replenishing. My desired negative is one with contrast in the lower values and reduced contrast in the high values of the negative. TMAX RS works great for what I want. I am now going on 1 year 4 months using Tmax RS and I only develop 2-3 rolls per month in it. The more you use and replenish, the better it gets.
SImply, after each roll you add a 45 ml's of the TMAX RS fresh developer you keep in the other bottle to the used developer, this keeps the PH and activity up. When bottle #2 the replenisher is used up, you can either buy more Tmax RS and keep replenishing after each roll developed, or start over. I know of one person who has been using it for 2+ years. It looks very dark and grey, but it develops beautifully for the type of negative I want.
For more information from Kodak on this,
click here:
Some of my work here in the Media gallery shows negatives developed in TMAX RS, the results speak for themselves.