I used DD-X when I was having problems with Xtol for 35mm and 120, mostly TMX. I found it has much the same characteristics of Xtol in terms of sharpness, shadow detail and grain, but I still give the (narrow) edge to Xtol in overall quality, especially with faster films. I could never get 35mm negs I liked using DD-X and Delta 400. I much prefer the look of Delta 400 developed in ID-11. But I've gone back to TMX and TMY in Xtol as my standard films/developer combo.(posted 8240 days ago)