In general I find presentations at conferences not all that interesting; I've been to conferences where I've not attended a single presentation. There are some good talks, but they're not common. Giving a good presentation requires a few different skill and some practice – I'm not good at it either.

The value is mostly in hanging out with various people. The best experience has generally been when I went alone and met loads of new people, instead of going with coworkers or friends and then just hang out with them. Not that's not fun either, but I can do that next weekend anyway.