I was quite unsure about the line when it was first announced, but once the Friends were released I've been hooked and bought all of them except for one polybag I can't find except on Bricklink from Europe at an exorbitant price. I even bought doubles of the treehouse and I'm thinking of getting an army of Karate Emmas and a few more squirrels. The sets have great variety and I love the fact that we're getting normal stuff that I actually deal with in real life like houses, shops, restaurants, cars, boats, pets, etc. It's not that I don't like the police or the fire departments, but those are two things that I don't really want to deal with in real life! Call me boring, but...
The new parts (especially silverware and other kitchen tools) and animals have been very useful and cute. Part count/dollar in these sets has been very good too. And... it's always good to have new colors!
To top it all off, I really like the minidolls, just need more guys so we can have a slightly more well rounded Hearlake City. But I'll keep buying them even if they keep making just girls.
Overall I completely love these sets Even to the point of putting off other LEGO purchases in order to get more Friends!