After about 2 weeks of waiting for my local store to stock it I have to say that the wait was worth it. The perfect ruinous power for my style of play is here and so far I'm loving it.
Everything now seems to be easier to backstab and to leech onto others hardwork. Moving around the board to position yourself all of a sudden in some other gods "safe" territory just so you can get in on the ruiner action. Or interfering with fights by just hanging around in a region I have NO business in anyway, proves a great distraction for the plan you don't actually have. Spreading Skaven tokens about for 0 power cost and placing 2 ratties for the cost of 1 means more power for longer as Khorne and Nurgle eat through theirs rapidly.
It's great to be the one god that doesn't excel in anything, have any real motivation besides ruining everyone elses plans, and to have no focus what so ever. Our games feel a bit more relaxed knowing that the ratties bring more fun and chaos to Chaos in the old world.
In my opinion, the new miniatures are so much better than the main boxes miniatures. They are just sturdier so I feel a bit more comfortable with other people handling them.
If this expansion is anything to go by then I really do hope that at some stage down the line another expansion is in the works for this great game. Oh and in our first expanded game, the ratties had a joint victory in the penultimate round along with Slaanesh the bas'. Though that might be because nobody could think of a counter besides chopping them into bits...but they just keep'a'comin!