How do you interpret Mahler's 7th symphony?

Mahler's 7th has always puzzled me more than any of his other works, particularly the finale - I can't decide whether it's genuine or sardonic. The end in particular feels exaggerated to the point of comedy, the horns in their high, strained register, the stampede of cowbells beneath them. Also the fact that it's a riff on one of the main themes of the sixth symphony. That motif, the third falling to the tonic begins in minor in the sixth, but is transformed to major by the end of the first movement. Of course the sixth ends in tragedy though, so it feels to me like it's poking fun at the optimism of the first movement of the sixth.

I could absolutely be over-thinking it though, I know a lot of people prefer to take it at face value, so I'm curious what other people's thoughts are.