I was a first-time attendee this year, and I had a wonderful time at InstructureCon! I learned a lot, met some great people, and really enjoyed the experience overall. A few more specific pros/cons/suggestions below (imho):
Sessions
Pro: Lots of great topics to choose from in the various breakout sessions.
Con: All of the sessions I went to were pretty talky and not very interactive. There wasn't generally much time for Q&A or for more in-depth engagement with the speakers where they could show you in more detail HOW they were accomplishing some of the various things they were doing.
Pro & Con: I'll also say that in the sessions led by instructure folks (roadmap, quizzes, etc.) it was great to see more details about what is on the horizon. But, while I totally get that timelines have to be flexible, even wide windows of potential release dates were hard to come by. It would be great if some of that could be worked out in advance, so the presenters can feel comfortable sharing at least tentative timelines for changes/ new features.
Suggestion: Maybe sessions with a potential interactive/hands-on component could be given a longer timeslot and maybe a room with tables to accommodate people bringing laptops? Maybe you could use one of the booths or rooms to set up a few computers and schedule some small-group follow-up discussions/work sessions with willing presenters. The "open lounge" could have been a good spot for this, but it was nearly empty any time I wandered over there.
Staff
Pro: Plenty of staff on hand to point you in the right direction, hand out ponchos, give you a demo in one of the booths, etc. and everyone was super friendly. Special shout-out to the dev folks in the UX tent! They were all very nice, willing to share what they're working on, and really receptive to feedback.
Con: None. Everyone was lovely.
Location
Pro: It was frickin beautiful in Keystone. The mornings were lovely, and there is no way to control the monsoons, so I wasn't bothered by the rain itself. The rooms were generally large enough to accomodate the audience, and while travel between buildings was sometimes a hassle, I think it was a reasonable tradeoff for the location.
Con: Not enough places to get out of the rain during meals/events. Handing out ponchos was a great idea, and I had rain gear, but by the last night, I was a little tired of standing in the rain.
Social Media
Pro: I use Twitter pretty heavily when attending conferences, because it's how I document the experience for later review and share it with colleagues in real-time. The social media folks seemed to be pretty on top of sharing things via twitter and retweeting interesting posts, so I appreciated that.
Con/Suggestion: It would be great to have an easy way to find the presenters on Twitter (if that's something they use). Not everyone is searchable by name, so maybe social media links from the session info in the app or from the event page on the community site would be helpful?