I currently have a waterfront listing on 3rd lake in grayslake and know a bit about lake front property. First question is the lake motorized or not. Some people want a quiet fishing lake, some want to water ski or jet ski. 2nd question is lake frontage, my lake house has 50 feet of frontage with a private pier. Some lakes have community piers where you have to lottery every season to get an assigned spot, changes from year to year. Being on the chain is way overrated to many boating enthusiasts, it has gotten crazy, loud and dangerous on summer weekends. If you want to party on the water or take your speed boat through 8 feet of weedy channels the chain is great. Channel front is the biggest joke of all. All that means is you can troll for five or ten minutes before you get to a navigable body of water. Beware of channel front homes, basically a manmade rivlet to allow more people water access.
As for the houses on lakes, many are former cottages on pier & post foundation, never meant for year around living. Often the older construction is settling and the foundation is unstable, built 75 years ago.