Location, selection, population. Usually these are the only three criteria I use to determine where I'll spend my coffee capital.
Often the closest places to me are way overcrowded at peak times, or the quiet spots with great treats just aren't worth the trek on a rainy Sunday.
But sometimes it is worth noting the Coffeehouse Couch-Stink factor.
I think it is a combination of second-hand upholstery, lingering hippies and constant espresso machine steam that creates this unmistakable coffeehouse odor.
Prime examples would be Palio Dessert and Espresso House at Ladd's Addition and Common Grounds Coffee House on SE Hawthorne. In fact, SE Portland seems to corner the market on the most Couch-Stink offenses...Fireside Coffee Lodge, Blend, Sweetness Bakery and Cafe...
Not to say that any of these places are unclean or bad choices. Just that maybe this is just another colorful difference between those sterile grab'n go coffee bars, and those living room coffee houses that seem to say "hey stranger, sit over here, relax, I think someone left half a veggie sandwich between the cushions."