One of the reasons that using the "big 3" hotels is so important is that the busses stop running to the outlying hotels after some totally rediculous time like 9 pm. Most of the important "networking" is just getting started by then! :)
I would suggest that each conference ...
You know we already got a big bump in price this year, couldn't you include parking passes for attendees at least? Not all of us can stay at the Swan or Dolphin.
And have it in Late Fall instead of dead of winter where the weather in FL is hit or miss. People who want to fly in can still fly in and if folks want to drive from the continental US, it's more centrally located. Plus I'm betting the conference center ...