Pets are fantastic, but the rest of the pack is a little disappointing.
I will go with the good stuff first - the pets are fantastically executed with great animations and interactions with the sims. A lot of time was spent on allowing players to customize the looks of their pets, which is good, but must have come at the expense of other features. The pets are really worth buying the pack for, but if you're not enthralled by the idea of your sims having animals you might want to give this one a miss.
I say this because apart from pets, the pack is really limited in terms of new objects, clothing, walls and floors. Perhaps EA just wants players to buy the stuff packs, but there are really very few new objects apart from some pet objects and a little new furniture. Your sims still have the same old fridges and bathroom objects they've always had. There are no new themes like the Greek in University or retro from NightLife as far as I could tell.
Some of the new building options are handy - diagonal roofs being the standout here. It's hard to get too excited about this becuase they really should have been included with the base game. The new 'sledgehammer' tool is handy but again it's surprising it's taken them four expansions and two stuff packs to add it.
Overall the pets are excellent, but only buy this game if they excite you because otherwise you're likely to be disappointed. If it's new objects you're after, save a little money and buy the Glamour Stuff Pack. On the other hand, if you're a completist like me you'll probably still be pretty happy with it, like all of the Sims 2 expansions the gameplay does flesh out the more you play it - not all of the new stuff is evident at first.