The Irish course is much more than a meager "solid second" at Whistling Straits. Sure, it doesn't have the lake views the more famous Straits course has (although there are a few), but the shot values are still remarkable.
Most mid-handicappers may even enjoy their round on the Irish more. It's landing zones are a little wider and lacks a bit of the intimidation of the Straits course. There are plenty of memorable holes too, like the par-3 13th, "Blind Man's Bluff," which features alternate tee boxes. From the top tees, you have a blind shot over dunes to the giant, 14,000 square foot green. From the lower tees, depending on the pin location your shot may be blind as well.
The Irish course is about half the cost of the Straits course at $150 and does not require a caddie. Those who book golf packages through Kohler also have the opportunity for free replays here as well.