Yes it's big—but is it beautiful?
Let's get this out of the way immediately: if you loathe opera or cannot stand musicals in which all dialogue is sung, don't waste your time and money. You'll hate it. Otherwise, proceed.
When I lived in New York, I went to the Broadway production of Les Miz and endured 40 minutes of vicarious misery as the dirty and starving, but vocally talented masses sang their ravaged hearts out. Flipping through the playbill, it gave no promise of this sad lot's future improving. I was an emotional coward. I left.
In the intervening years, I have gained emotional strength (and the fore-knowledge of an uplifting last act) and saw the film through to the end. True to the complaints of some, it is larger than life and over the top. Well, duh. Of course it is! It's about romance, revolution, and redemption. Are those subjects you want covered in tiny, subdued subtext? I think not.
It is gorgeous. (Hugh Jackman—although marvelous in the role of Jean Valjean—alas for the first time ever, is not.) It is stirring. It is even hilarious when Sacha Baron Cohen and Helena Bonham Carter bring their sleazy characters to life. The music will send you scurrying to iTunes, and the musical finale will thunder through your head for days to come. (Could be worse—e.g., "It's a Small World".) Go big or go home. Go Les Miz!