One way to never be able to get the same results twice, be they good or bad, is to constantly be switching films and developers. Pick a few things and stick with them until they are nailed down, IMO. There isn't much one cannot do with a simple general purpose developer like ID-11, Ilfotec HC, or DD-X. But always switching from one to the other simply because your last roll didn't turn out well will not serve you well. There is nothing wrong with any of these developers, or any of Ilford's films, that will cause bad results related directly to the materials. Metering, developing, and printing are the likely issues that cause people to say they dislike a film or developer. But most developers and films are very general-purpose oriented, and with diligent technique and trial and error, any combination of standard film and standard developer can produce results that are great. We each just need to put in the time to learn how to work with them.