hmmm... methinks they did all their research via the internet, and perhaps haven't actually visited any of these stores... At least, judging by their comments on Mississippi Records in Portland. It's an amazing store, but very small and rather specialized in their offerings. Their old blues reissues are highly recommended. "The largest record store in Portland is Jackpot." Uh, sorry but no, not by a long shot. If you're passing through the area, other must-see record stores would be Music Millenium (the oldest and largest indie shop), Jackpot (a hipster's wet dream), Green Noise (a garage punk mecca and home to Dirtnap Records) and 2nd Avenue Records (a little pricey, but STACKED to the rafters, and full of rare stuff you usually have to find online).
Glad to see Reckless Records (Chicago) on the list, they're incredible. For Chi-town shops, Dusty Groove probably should've gotten a mention too. And jazz hounds MUST visit Jazz Record Mart at least once in their lifetime - the largest collection of jazz records in the world, with stuff you could spend decades searching for.