Niall,
A great matchplay course IMO is one with a lot of variance in potential outcomes but may not be "fair" to the scorecard and pencil medal play set. Rub of the green, half par holes, wind, firm/fast etc. Where a shot that is too aggressive or slightly off line may lead to a big number, but where low numbers are also possible. Holes where you can make eagle or double and the difference may turn on one shot. I'd love to see the Ryder Cup contested, for instance, at Bandon. High winds, a different course each day, guys taking risks, getting eagles, birdies and X's. Balls bounding into cavernous bunkers that were more than a 1/2 stroke penalty. Of course it'll never happen.