I have 18,22,26 and 32kg competition bells because some years ago I got a good deal of them. It has always irritated me a bit that I have these funny sizes (and a competition models) and so I ordered a classic 16,24,32 set of hardstyle bells. (Which I dont have yet) Ever since I finally decided to order the new set, I have realized how much simpler it will make my choise of bell size for every given exercise, but I also have realized that having 4kg jumps available made do some bad decisions during the program. 1. When the jump to the next bell is smaller, it`s tempting to start using a heavier bell sooner than you could with "By the book" bells. Even if you can pass the time standards, it`s intended to spend more time until you really own the bell and rather change the way you use the bell instead of chasing numbers. Very slow get ups etc... 2. Light days tend to not be as light, because you can go 4kg lighter instead of 8kg. I think having bells with 4kg jumps between them is good, if you really know how to use them, but I think it might be harmful also, because overall its pretty easy to keep going too hard on average.