I think that's a great idea if you are going to live next door and manage it yourself. Once you start hiring someone to book rentals, clean it, manage it, etc. you lose that extra income and then it makes better sense to rent it long term.
Most of my clients who do the AirBnB route manage it all themselves and either have a reliable cleaner on-call or do it all themselves, pocketing the 'cleaning fee'. Also, since I'm a broker in Miami, I have a lot of out of state owners so they tend to hire people to do more things. I can't speak to their ROI but its still better than annual rental.
BUT, that's Miami Beach. I don't know how Austin would do. If you are relatively close to all those events you mentioned, you should do well. As long as you price it cheap enough, you'll get lots of bookings/inquiries.
Be sure to rent it on VRBO/Homeaway as well and rack up the positive reviews. Then you can start raising the price once you have 10+ 5star reviews.
Don't be afraid to leave them some $3 Trader Joes/Aldi wine as a welcome gift too - that'll guarantee your positive review :-)
Best of luck!