I went on that last summer. It was a great time but mostly because of the company I had with me. Important FYI, the boat won't wait for you. I missed the boat leaving Lakefront Brewery because after their long-ish tour I had to run to the bathroom real quick. Completely B.S. that they left so quickly. Honestly, the Rock Bottom tour is a joke, but they get you into their cellar tap room quickly to get you drinking. The Lakefront tour is awesome and hilarious, I've done it twice. I skipped the Milwaukee Ale House tour to just drink instead at the bar.
A couple years prior I went to the Lakefront Brewery Tour while not on this boat trip. I have to say, that is definitely the way to do it. That place is awesome, the employees rule, their beer is pretty good but plentiful. All in all, an awesome place and easily the highlight of that boat tour. Hope that helps.