We used to go to Willow Valley on a yearly basis - end of summer/week-end trip when our kids were much younger. If you have children - this is good for young ones (unless it is their first time here). We all enjoyed it and took day trips to Hershey, Renaissance Fare, Dutch Wonderland, Kitchen Kettle, Strasburg Train, corn maze, shopping, etc. We had no problem doing this as a family - as they got older we went with friends who had children same age. We also did an adults only week-end one year.
Willow Valley is a great/clean, family, oriented resort. There is a 9 hole golf course on site and tennis courts. It is owned by Mononites so no bar/entertainment in the eve. We used to bring/buy our own liquor/beer. You will need to drive to anything/everything - museums, restaurants, amish tours, etc. You will find most places closed on Sunday - have only been here during summer.
We love it and miss it - my older kids of course have no more interest here. My youngest (13) is always asking me when we are going - of course, she would also go if friends came along now.
If you are going to relax and spend time with family and friends - you will be fine.