I liked them both, really.
Swap meet: I got some harder-to-find and cheaper things (ChuChu Rocket, first half of Red Garden for $15), but most of the things there I had no interest in. Good for people who like more niche items and better prices, but there are no guarentees as to what you will find.
Dealers room: I got all my usual cutesy things (at the booth that at half off all Sanrio merch <3), which I'm happy about. Also, the Celga booth was <3, even if I totally can't afford brand. Still the same crop of merch for the most popular series and overpriced items (and some bad loli clothes...), but I got what I went there for.