As a resident of Seattle for almost 15 years, I've come to feel that while Seattlites are generally very friendly on the surface, there's a solid wall that most people have up that keeps us from really getting to know people outside our social circles. This also carries over to merchants, who in my opinions are very stand-offish and generally could care less about extending the common courtesies and personal touches that make a customer feel welcomed and appreciated.
The Tasting Room is the complete opposite of this. My proof is in the fact that I know the owners name and she knows mine. She remembers me when I come in, even though there may be months in between my visits. She remembers what kind of wine I like. She even noticed the ring on my fiance's finger after we got engaged.
The real beauty of a wine tasting room in my opinion comes not for connoisseurs, but for novices like myself. What better way to discover what you like and don't like than the change to sample the options with a knowledable and helpful guide. Which again brings me back to the service. They're very attentive and carry not an ounce of snootiness. And they're great advocates for our Washington wines.
One final selling point: location! It's tucked in between the Pink Door and Kell's in Post Alley, near Pike Place Market. The room has lots of old wood, exposed brick, almost European feeling. It's a great place to bring locals and out of town guests.