Steve,
I'm the one who did the photo-thread on Koninklijke Haagsche (Royal Hague) a few years ago. Last time round this track for me was yesterday.
Royal Hague is one of my favourite courses in mainland europe, and indeed it can certainly compete with some of the top courses in the Surrey sand belt and other courses in the UK which are let's say not top 50 world. It is off the beaten track, few people travel to play here and certainly very few Americans ever have laid eyes on the course. Probably that is why it gets overlooked in the rankings, (like De Pan) also until recently maintenance and upkeep were not up to par with courses in the UK. However that has improved recently and also renovation work by Frank Pont has enhanced the Colt/Alison heritage of the course. Some of the changes are being implemented at this time, including some new tee's on 14 and 15 and massive clearing of small trees and bushes throughout the course.
RHague, despite some semi-wooded holes, is a links course and therefore hard to compare to Sunningdale (which I have not played), or Morfontaine (which I have played). Although the course is not wide it probably is the most strategic course I have ever played among courses with limited fairway width. Among the links courses in mainland europe in my view it is the best by a margin.
I have played 15 of Golf mag world top 100, 34 of GW top 100 europe, including most of the classics, and if I would have to name one course which is underestimated because of location and upkeep/maintenance issues in the past, this would be it.
If you go there by this summer all of the changes and clearing should have blended in nicely and you won't regret it, if you travel to play here. My advice: combine with De Pan, a wonderful heathland course, totally different, but of similar quality.