Relaxing and tranquil atmosphere, good separation of seating area from retail and counter/ordering area. Wide variety of teas, with the most delicious bubble tea I have ever tasted! I highly recommend the green almond tea iced... It's sublime. My only criticism is that it's a bit out of the way and has relatively no foot traffic, but this also means it's rarely crowded.
I am a huge fan of TeaSource and their excellent selection, wide variety of events, specials, and merchandise. The staff are generally friendly and fairly knowledgeable about the selection of teas within the shop. I am especially fond of their Sample Tuesdays, where they cup five different teas based on a central theme (i.e. Chinese Greens, Holiday Teas, Herbal Favorites) and serve it to you on a tray for a mere $3. It's a great way to try a tea you might have otherwise never thought to. Their pastries are ALWAYS delicious - I'd highly recommend the Lemon Cream Cake, but the Chai shortbread is amazing as well.