Instructing has improved my flying, my situational awareness and my CRM immensely. I am fortunate that it will also be directly relevant to my future career, as I don't have "big shiny jet" syndrome, and so many of the operators I want to work for ask for hours (often an AOC requirement), but don't have a blanket negative response to instructional hours.
However I would also be far more confidant in a sim check - my currency and improved handling skills certainly showed when hand flying a Tristar sim during an auto-pilot malfunction on my MCC (assymetric engine out as well), correct basic flying skills apply as much to a big jet as to a PA-28! Whether I hop into a Kingair or a 727 sim after an interview, I can impress more if I have done 400 hours in the last year as a part-time instructor than if I'd scraped together 20 hours plus an IR renewal!