It's always interesting listening to music with lyrics in a language I don't know, because so much more of my understanding depends on the vocalists' interpretations of their parts. (The Met Opera has electronic panels on the back of each seat displaying translations of the lyrics, but I tried not to rely on that, because watching the staging of the production is a huge part of the experience.) You can always get a rudimentary understanding of what's going on, because there's enough overlap between the various Romance languages (though that leaves German lyrics nigh impossible), but the nuances are really up to the vocalists, in their facial and body language down to the minute inflections of their lines. For instance, in this production, the audience could tell in the first act the exact moment when Benoît loses control of the situation at Rodolfo's apartment -- you could tell by his posture and the vocals of the other characters how inebriated he was getting.
Another element I've noticed: it's hard for any stage performance to adequately develop character, because it's constrained to about two hours, and there's only so much of each character that the audience gets to see. I do like how -- other than the marketplace scene -- Puccini doesn't include any group or choral numbers. The opera focuses narrowly on the lives of the six central characters -- and really only three or four of them are developed at any depth; the small cast lends it a sense of intimacy that you don't often see in some of the larger, more traditionally theatrical operas in the repertoire. It would be a good choice for an indie opera house -- I'm not surprised that Rent (a very creative update on La Bohème where everyone dies of AIDS instead of tuberculosis) remained an Off-Broadway production despite its success.
Now I really must see Rent. I missed both the original production, which closed when I was in high school, and the revival, which went dark quite recently. (I have the soundtrack to that, as well, and I do like how Jonathan Larson includes so many nods to Puccini.) I've heard mixed reviews of the film, but one of these same friends is organizing a screening of the original production -- I'm super excited! :-)