Yes, I have done some parts work and found it useful. It has helped me make sense of what I do and how I feel and why. The idea that there are no bad parts and that every part exists for a reason has been helpful. It has been particularly important for me to understand my Protectors (link with explanation) since sometimes they react in ways that don't make sense to me or don't seem terribly helpful in my current circumstances.

Note: I don't have dissociative identity disorder or anything, so these aren't alters but rather different feelings or ways of reacting. It has a similar feel to the way one might say, "Part of me wants this, but another part of me wants this." IFS (Internal Family Systems) lets you explore both of those parts and help you figure out how to get them to work together.