SEU is a great event because you get to hear from SE employees, partners, and top shelf users as well. Depending on your interests, there are a lot of experts to hear from, and you can get access to just about anyone. To get the most of it, you really need to spend some time with the list of sessions (which should be coming soon) and plan who you want to see. The presentation files for most of the sessions are available after the show, but they aren't the same as getting to sit in the room and ask questions.
There are also some fun events, and free time when you can schedule what you want to do. The roundtable sessions are great to have input into specific new functionality. You'll probably meet people you've talked to here. The information is very valuable, but the most valuable thing you'll gain will probably be the relationships you develop with people you meet. It sounds a little corny, but its true.
And often there's stuff going on that you can't see anywhere else. Like who knows, maybe a sneak peek into what's happening in development for the next release. Or new products in the pipe. You can probably talk to Jeff Walker, or Dan Staples or Laura Watson or Aditya, or Gan or Art Patrick, Dan Vinson, Doug Stainbrook, or other people who's knowledge of areas of the software is truly legendary.
So yeah, it's a great time, and you can make a lot of it. Just take some time to do some research and plan it out.