My fraternity (yes, fraternity - not sorority) hosts their annual alumni holiday dinner here, the most recent being last night, and it is always one of my favorite events. We always reserve one of the side banquet rooms, which gives us the privacy we need.
The ICC staff are consistently wonderful to interact with. The valet, coach check attendants, bartender and waiters were all very courteous and accommodating for our large party. Beyond the service, the food is always good - my particular favorites from last night were the risotto and chocolate soufflé. I had to show some serious restraint to not eat the entire dessert, otherwise I would have induced a food coma.
This review may not be the most helpful considering you have to be a member (or in my case, a fraternity brother of a member) in order to visit, but I recommend Interlachen regardless.
Having never been to Interlachen personally, I am leaving a review of their staff that I have dealt with over the phone.
A few people in my office are members of the club, and I regularly make reservations for dining and sporting lessons on their behalf. The staff at Interlachen is friendly, courteous, and easy to deal with. They return calls in an extremely timely manner, and are great at squeezing someone in for a last minute need.
Blake, the Clubhouse Manager, is a really fab gent. Very accommodating and awesome. Don't hesitate to be in touch with questions or requests!