I like Tuvalu. I've been to many MANY coffee houses (my husband and collect them like trading cards), and I've got a pretty set criteria of what I want them to be.
Tuvalu has a lot of neat things. I wouldn't call it as "trendy" as the shops on the East side of Madison, but it is a comforting sort of place. It feels very homey from the moment you walk in. Tuvalu also includes a really cool little shop of handmade items ranging from artwork to jewelry to household items that serve as a fun gallery even if you're not interested in buying. There are lots of fun things to look at, and the artwork within the shop (also for sale) seems to rotate fairly regularly as well.
On Fridays, Tuvalu also regularly offers various acts. We came for a father-daughter team that offered a lot of current hits, often performed in a more soft-rock style well-suited to a coffee shop atmosphere.
Tuvalu also offers food, which is always something I appreciate in a coffee shop atmosphere. Some of their items are better than others, although I haven't had much. Some tasty items I've tried have included a spiced muffin and an EXCELLENT chocolate peanut butter pie. I was somewhat more disappointed by the breakfast burrito, which was small and had what tasted like canned salsa inside it. I have yet to try any sandwiches or larger items in order to comment on those. Coffee drinks (lattes) were decent but not exceptional.
Overall, a very solid shop that most definitely has a great small-town feel. It also seems like it is a great neighborhood gathering place--people coming into the shop are often familiar with the owners/employees.