Personally, I *DON'T* think the Crown Rooms are worth the cost. I *DO* think the World Clubs are worth the cost. The difference is food.
WorldClubs tend to have enough options that you can substitute for an airport restaurant in most cases - either to get you the three hours to a restaurant outside the airport at your destination or at least to a meal on the plane if you have the upgrade.
Crown Rooms - not so much.
And without suitable food options, have to spend 45 minutes at the restaurant, and at that point $300+ will buy you a whole lot of beers. And beer will buy you a spot at the bar you can sit and do work.
I suppose the CRC's might still be worth it for people who require absolute quiet, but I'm not one of them.
Oh, and also, factor in the cost of tipping to your CRC membership, which is not a WorldClubs hidden cost.