I also found Peer Gynt to be less weighty than I expected. The core question, "What is the difference between a troll and a man?" doesn't seem very difficult or nuanced or even meaningful. As I read, I wondered if my lack of appreciation could be linked to reading the work in translation and thus not able to appreciate the poetry, or to lack of familiarity with Norse myth and legend. Still, the story itself didn't seem terribly significant.
I found it to be enjoyably witty and parts were touching or sad. As Hamlet said, entertaining in a performance as a night out, but fairly trivial as a read.
I'd love to see some comments that will help me get what I'm missing. I also hope that once I have a little more time over the weekend I'll have something more cogent to offer.