If the staff really likes you they'll give you a coupon for 1 EUR off your next purchase from them.
A good selection of books and some comfortable seats on which to peruse them, a relaxed atmosphere, and a good selection of Debbie Bliss, Opal and Noro yarns (and a hank or three of Colinette!) they also have an interesting array of notions on hand. the customer service is excellent, and be sure to ask for a customer loyalty card (get it stamped with a minimum 20 EUR purchase 10 times and get a 10 EUR customer gift card).
the place is only a few steps from vihreä Vyyhti as well, so you can probably visit both LYS in one swoop if you have time!
There is no seating at this yarn purveyor (it's more of a kiosk than a walk in shop), but there is a cozy coffeeshop within arm's reach of the place where you can knit and people watch if you like.
Half the store is devoted to well-made handknitted goods, the other half to finnish yarns and a large selection of buttons.
No seating or anything, but then again the store isn't very big. An ok selection of needles and yarns.