delayed onset muscle soreness is neither good nor bad.
its caused by numerous things, most of which are not beneficial for size (variation, ultra high reps, overworking, etc) and others which some consider to be good, such as training to failure (god knows im not getting in to this.. i dont think its productive but i put it aside because so many believe it is) however, this does not mean all soreness is bad or anything, I get sore often when I do something different or push myself a bit harder on something. the reason I believe DOMS is not great is because it screws up recovery (from hardly at all to a ton depending on how sore you are), which isnt productive at all.
i see it as a side effect rather than something that i should really concern myself with, I rarely ever am sore for longer than a day or two (unless I do something like 20 rep squats or a training camp for fencing), so it never really interferes. if i dont get sore it doesnt mean i did something wrong, and if i get sore, great, who cares.