I recently switched from Ilford ID-11 developer to Kodak HC-110, mostly because of the increased shelf life of HC-110 (syrup as old as from 1979 kept in half-full bottles have been known to work). It’s also a lot easier to work with since you normally use around 10-20ml of concentrate to make 300-600ml of working developer.
My only setback so far has been the first roll I developed with HC-110. As you can see from the picture, the negative turned out very overdeveloped, since I used times given for the older formula for Tri-X (TX) and not the newer 400TX that Kodak sells these days.
The interesting thing is that the variation in time isn’t that big, 8 minutes in dilution E seems to be about right for 400TX shot at EI 400, while 7 minutes and 30 seconds in dilution B rendered this. On the other hand, maybe I should have used some of my intelligence and figured out that if the The Massive Development Chart noted 7 minutes and 30 seconds in dilution B, and Kodak recommends 3 minutes and 45 seconds for 400TX in dilution B, something isn’t quite right.
Anyhow, there has been a lot of debate about this online, and people seem to agree that the optimal time for 400TX in HC-110 is somewhere between this two massively different times. Another theory is that Kodak messed up their testing and that the time posted by them is actually for 400TX in dilution A.
Update 15 Dec. 2011:
I’ve received a lot of emails about this post asking me if I’ve found a better time. And yes, I have, currently I’m using 8 minutes in HC-110 dil. E at 20 degrees C for Kodak 400TX at EI400, and that has given me nice negatives with normal density. The over-developed negatives had about twice the density of the ones I’m getting now. Hope this helps, and please comment if you have ideas/suggestions!