This just in from Bloomberg.com: Generation Y reports a strong affinity for three hotel brands among seven other brand rankings. The Ritz-Carlton and Four Seasons rank second and third among Gen Y females, while W Hotels ranked eighth. Hotel brands were less preferred by Gen Y males in general (many brands in their top 10 were car brands), but Four Seasons and The Ritz-Carlton did rank seventh and tenth, respectively.
The L2 Gen Y Prestige Brand Rankings, which looked at 105 iconic brands, surveyed Gen Y high-earners from 45 countries. This brand-conscious generation, also known as the Millennia Generation or the Next Generation, falls into the "under 40" category - a category that many of your attendees likely fall into.
Considering that this survey of Generation Y respondents was merely to uncover the top prestigious industry brands, and wasn't exclusively about hotels, it really says a lot that these three hotel brands made the top 10 hot list. If your attendees do in fact fall into the Gen Y category, perhaps it's worth considering brand recognition as a factor in your site selection process.