The food options change on every tour (among other bites, our tour featured yellow potato curry dumplings from Dump Truck, which we would book a flight back to Portland for anytime), so be open-minded. But it's not just about the food; Burmeister also talks about the way that the food trucks have changed along with Portland, how the vendors utilize public space, and how immigrants from different countries have put their own personal stamp on Portlandia. He also knows most truck owners/chefs personally and will give you a backstory on everything you eat along the way.
Book the tour in advance so that Burmeister can accommodate food allergies and preferences. If you’re interested in particular cuisines (like trying multiple takes on dumplings, only desserts, or falafel from every country in the Middle East), coordinate with Burmeister ahead of time for a special tour.
This should go without saying, but make sure you wear comfy shoes (you will only go to downtown-area carts and trucks, but they're not all next to each other) and bring your own bottle of water.