SunshineMom - I have seen your posts and wish I had more relevant information to give you. I grew up in Washington, and my family still lives there, but I have lived away for many years. What I know is limited knowledge.
Basically, if you live in the Washington school district, there is no school choice except to go private. What I mean to say is that there is a school that does K-1, another for 2-3, etc. Living in a large city like Durham has made me wistful for such a simple situation.
I looked at the test scores for Washington not too long ago, just curious to see the current scores of a system that produced me. I thought for small town NC, with limited economic resources and mixed demographics, the schools were doing OK. You'll find test score info at
Washington Schools. Of course, you should keep test scores in perspective - there's so much more that makes or breaks a school!
If you like church life, you and your family could find a secure home in Washington. That seems to be an excellent source of social contacts and events. If you have the interest and finances to purchase a boat, or to make the river your focus of family activity, Washington may have a lot to offer.
Greenville definitely has more shopping, more restaurants, and more nightlife (with three children I'm guessing you're past the nightlife point!). I lived there for a year or so several years ago, and while it provided more city-type things, I was irritated by the traffic. My then boyfriend would visit from Durham and it was basically dinner and a movie - not much to do. Yet, my cousin and his wife live there with their two small children and they love it.
You'll find a lot more chatter about Greenville on this board than Washington. Hopefully someone can come along with more recent knowledge about life in the Original Washington (as it likes to call itself).