I did another session using Ultra Black last night with a wider variety of negs. I am trying it because I want to get more snap in my shadows without going to additional toning steps. I have to say that it gives a noticable improvement in that area. I am liking it so far.
That is of definite interest to me. This sh...ahem...stuff is pretty expensive next to Dektol and I haven't been printing all that frequently. I gave my bottle of stock solution a poot of butane as suggested by various arsonists here on APUG to displace the air in the bottle. Hopefully this will extend it's usable life. I'll let you know how it works out.
On the topic of paper developer shelf-life: I split a gallon bag of Dektol powder into sizes to make indivdual quarts and bagged them in zip-lock bags. I was amazed at how quickly the powder discolored in these air tight bags. When mixed it is the color of strong tea. I'm going to try it again using a vacuum bagger/sealer and see if that works any better.
Would you mind telling me the dilution, dev. time and paper that you are using?