papa: I've done this twice, most recently in May. Besides the comp room, you get a 7x multiplier; I believe it lasts for the duration of your stay. The cash grab is limited to 75 invitees although sometimes they accept more and up the prize pot accordingly. The actual event takes place in an expanded hotel conference room - both times I attended it was a Tues afternoon around 2:15. They serve a build your own sundae spread, plus a few assorted pastries, like brownies and cookies, plus coffee and tea. Invitees can bring one guest; guests can do the sundae thing but not the cash grab. When you arrive, you draw a number from 1-75. They call you up to the front in groups of ten or so, line up in numerical order, and pick one at a time from a table of gift giveaways that they never gave away - the gift isn't the prize. Attached to each gift is a tag with a monetary amount, which is really what you win. Prizes range from $50 to $500. Most of the prizes are $100. Considering it's all gratis, a pretty good deal.
fredo