Can someone tell me if the original woodwork in a house adds to the value? Or is it better to have it updated?

The issue is the age of your house and the detail of your woodwork. I live in a house from the 40s, not a time known for woodwork, so I've replaced. I grew up in a Victorian, circa 1900, keep the woodwork. My brother lives in a 70s style home, ditch the woodwork. My Grandmother lived in a house in which the woodwork was all forest pine and hand carved, save it. I guess the answer for you is pretty obvious in your question -- your woodwork is so plain that you want to bring in something nice, so do so. There is no value to plain.