I notice that he recommends the Garden Grill among the lowest tier restaurants. We ate at the Garden Grill before our CP show - and I warn anyone that is thinking about doing this: it is a HIKE from the Garden Grill to the American Gardens Theatre!! We were seated pretty late and by the time we got out, we almost were running through the crowded park - and it had already started! Luckily there were still some saved seats.
If you wand to do GG, my advice is book dinner AFTER the show OR book at least 2 hours before the show and check in 20 minutes early!
We are going to try Biergarten this year - Germany is quite close! I have yet to eat there, but other reviews say it is above average.
Last year we did Marrakesh, which was great, and extremely convenient to the show.