Two reasons why this movie is a good reason to watch: the first is the visuals. Rajastan is a beautiful place for sure, but dear god, does this movie make the most of it! There where times when I was actually holding my breath in awe of the sheer visual poetry that flashes across the screen.
The second reason: the acting. All the other commenters already cheered Big B's performance, and true, he really reaches unsurpassable form here. But be sure to also have an eye for Shroff, Irani, Sanjay Dutt and Saif Ali Khan: they also give an impresssive performance.
What's less good of the movie is the way the characters develop. VVD has a goldmine of a storyline here but he fails to mine it: we could have easily seen more of Big B's doubts about dharma, more of Saif Ali Khan's uneasy steps on the path of palace intrigue and treachery, more of Dutt's feeling as a scheduled caste DSP involved in outdated monarchical madness,more of Shroff's agitation as the king's younger brother - the story now is told in such a way that it leaves you guessing too much at what the characters would be going through, so that at the climax you recognize: this would have been a heart-breaking tragic scene of more then epic proportions, if only you would have felt more...
So,all in all, a good performance and a great visual tour of Rajastan - but not the brilliant movie you can easily understand it could have been.