Poughkeepsie here, I'm with those who have advised against zoysia. It is a southern grass and is not designed for zone 5. It does have benefits but, there are compelling reasons for not using it in our area. It was developed during the Korean War to stabilize airfields then popularized in the 60's and 70's with newspaper adverts selling sprigs. The lawns that you see in our area with zoysia most likely are many years old the new owners have inherited the problems associated with it. Heaven forbid that you get started then decide that you don't want it because it is extremely difficult to eradicate.