The Merchant of Venice, true to William Shakespeare's play, is a hell of a movie. Stellar cast, wonderful acting, beautifully filmed, blah blah blah.
Al Pacino is terrible in this movie. Terrible! He chews the scenery! Shylock is not a role I'd want to play, were I an actor, but ... blegh. That's the best I can say for it: blegh.
Jeremy Irons is good, in the role of Antonio. Somewhat overwrought, but good. Joseph Fiennes is terrific as Bassanio, he who learns. The "I refuse to believe they're not lesbians" duo of Lynn Collins (Portia) and Heather Goldenhersh (Nerissa) are as good as they need to be. The real stand-out, for me, is Shylock's daughter, played with understated grace and feeling by Zuleikha Robinson.
Overall, I give this film five stars for authenticity, 3 stars for "believability" (and this does take into account that it is Shakespeare), and 2 stars in that nebulous category: "I should care about this...why?"