hi there!
i'm a member of "i-played-that-last-year" club also...

well, brahms is a quintessential composer, and this is quintessential brahms. what else could i say?
about the piece, some spots:
- to me, the trickiest part are the scales. although i must admit that my scale technique is not that good, it was the most difficult part to me, until achieving a smooth, flowing and fast passage;
- there are some killer leaps. it worth studying them in some depth, specially if you plan to play it live. studying several times just one, eyes closed, are the best way to ingrain it correctly to me.
- finally, this piece (like much of brahms) needs very much of your phrasing skills.
by the way, what are you curious about the quiet section's melody? in my experience, there was no problem in controlling that.
best!