I love the new apartments, I love how you can have several playable households on one lot and have them interact with each other. The ordinary lots seem so lonely now...
I love the new playground equipment and the playgrounds that come with a lot of the lots. Some of the playground equipment builds body skills which I think is a lot more realistic.
I love the ability to walk to school or work. Again it's much more realistic (don't have big yellow school buses where I live).
I didn't buy AL for the witches and one of the things I don't love about is how they behave on OFB lots. I have had up to five witches at a time on a sim owned lot and the spellcasting really annoying especially the cockroach spell the evil witches cast. On ordinary community lots your sims aren't there long enough for them to be a problem and they are not there the next your sim visits but on owned lots your sim really has to deal with them otherwise they are still there on the next visit to the lot and you can't call the exterminator to a OFB lot.
I don't think EA really thought through the impact that AL would have on features of other EPs.
But in spite of that I still love the expansion.