My name is Alexander, and I'm a 1st year PhD student at UC San Diego, and this is my first PLDI. I was prepped with the understanding that these conferences are, in a sense, primarily about networking. And this is probably the right thing anyway - ideally there is an exposure to at least a few ideas that seem personally relevant or interesting, and the opportunity to meet a good number of like-minded individuals from the community.
This has essentially been my experience. At this point I've attended a few talks that have been exceptionally cool (in my opinion). I've talked to people who weeks ago were merely names on DBLP - either about our work or about the weather or about the experience of actually getting to Beijing.
The best part is experiencing everything for the first time - which only makes me more excited to return to future PLDIs, whether to give a talk or just catch up with old friends. I hope to see you all again in the years to come.
P.S. it would seem a miss if I didn't plug something related to me, so you can read about the research that we presented earlier in the week at http://goto.ucsd.edu/~rjhala/papers/deterministic_parallelism_via_liquid_effects.html