Steve,
We have a business partner in Kortrijk, just 20 km to the west of Oudenaarde - and the whole area is really pleasant - just starting to get a bit hilly after the endless flat beach that makes up most of coastal Belgium and Holland.
I think you've done well to avoid the Kompas Nieupoort and Westende sites, these coastal sites are (rightly) very popular with young families and are jammed full during the Summer.
Kortrijk has a pleasant town centre - usual low countries thing of a big market place with restaurants around the outside. And you should be able to park close to the centre for free.
Gent is a big industrial city and whilst the centre is pleasant, the suburbs are very industrial.
The gem is of course, Brugge - but I guess you've done that before. In which case may I suggest the town of Damme to the North East of Brugge - just charming - the size of a village with five or six good restaurants and a few bars. And it's rather like where we live in the UK, which is probably why I like it.
Goede vakantie, Robert