Blizzardfire, that's a good question. I think it really varies by the school. I went to the one in Chicago; SAIC (where it was held) had upwards of fifteen or twenty people looking at attendees' portfolios, so it's anyone's guess whether your work would be seen that day (and, more importantly, remembered later on) by someone on the admissions committee. Some of the universities have smaller faculty, so there's a better shot of having your work seen by panel members there. Nevertheless, I think there is intrinsic value in getting your work evaluated by people from those schools even if they're not on the actual admissions committee. Ostensibly, faculty talk to one another and see the kind and caliber of work that is produced by the students and alumni at their institution, which means they should be able to gauge the skill and conceptual drive of your portfolio against that. The only downside to portfolio day is how late it is. They're held in late October/early November. Realistically, if everyone pans your portfolio, there's only so much you can do between then and when applications are due! (: