We had a Mac 26x, but sold it to buy a larger sailboat. We had it for 4 years, and sailed in the Chesapeake Bay. It sailed OK - not great, but still got us where we wanted to go, and we had alot of fun on it. What we enjoyed the most was being the shallow draft - we could anchor in places the 'regular' sailboats couldn't. And we often did - leaving Sat morning, sailing during the day, anchoring in shallow river overnight, then up and sailing again the next morning. There is a Mac forum MacGregorSailors.com
that has people from all over the US and around the world that are Mac owners. Several of them sail the Great Lakes, so they would be a reliable source for you. Good luck - and enjoy!