Portland's Best Burgers

The site Extra MSG has a rundown of Portland's best burgers. I acknowledge that lists like these are always subjective, but he seems to have made a huge effort to keep an open mind (and full stomach).
In the course of the survey he ate 72 different types of burgers, sometimes more than once. This required eating up to four burgers a day!

I noticed most of the burgers were laden with cheese and bacon. At that point I wonder why add the beef? I'm making a note to myself to try some mushroom "burgers" with cheese, eggs and bacon.

From the list, I've only had the Foster Burger, but the most distinctive sounding burger was from Biwa.

He writes: "Even if you took one of their thick slabs of chasiu pork with its well-charred ribbons of fat and slapped it between two pieces of bread, it might still be one of the best sandwiches in town. But you add a beef patty and some tart, spicy kimchi mayo, and you have one seriously addictive Japanese-style “ham” burger fit for a sumo in training. Too bad it’s only available late night."

Well, I might just have to make a late-night visit to Biwa.