1. I thought the attempt at humour failed a bit. Aishwarya Rai saying in the train "Hai re! Chain se ro bhi nahi sakte hum". Abhishek telling Motabhai "Tu itna badsoorat hai, is liye ro rahe hai", and so on, just don't work.
2. A better actor than Baby AB would have done justice to the role. Baby AB is unconvincing.
3. Aishwarya is zillion times more tolerable than in Dhoom-2.
4. Lot and lot has been written about the cinematography. Apart from the initial flourishes, it was pretty average. I especially dislike it when slow-motion is used and frames transition isn't smooth (less number of frames per second, which are unable to support them slow-motion). I don't know the tech jargon for this, but RDB also used it and it gets on my nerves.
5. The movie just talks in punch-lines. There aren't too many details about what Guru actually does to become that successful (Its literally a montage of 4 shots where his company grows from 10 people to 10000). I would have liked lesser time for side-plots, so that the main story was more elaborate.