Of course, you can always get finer grain, tonality etc by moving up a format. You don't say what format you use, but I find that the difference between my 6x7 and 35mm negs when using the same film is greater than the difference between HP5 and Pan F within 35mm. I must say, it was sad that Delta 25 was abandoned. I was a big user of Kodak Tech Pan, but I am coming to the end of the huge batch I froze when it was discontinued and was hoping that this might have given a real alternative without the drawback (to me) of extended red sensitivity. Still I am very grateful to Ilford for bringing back SFX for when I do need IR, so it's swings and roundabouts. Tech Pan was amazing stuff. The grain is so fine that it is actually difficult to see it in my high magnification focus finder when making 8 x 10 prints from 6x7 negs.