I've never played in Biloxi, but have in Tunica.
Cash games are very juicy there in Tunica (especially if you like limit games, the 4/8 half kill (or was it full kill? I really don't remember which way it was now) is really juicy), and there are several other casinos there where you can really clean up, since they have people that come there from as far north as Michigan to play there on a regular basis. Most of those people don't get much of a chance to play (live) poker, so the games are very soft in Tunica.
Based on my posts here:
http://forumserver.twoplustwo.com/showfl...=0#Post11529364
Tunica is also cheaper from a room rate standpoint as well (max rate a night for the special rate while it lasts, is only $115 a night, with most nights a LOT lower), since you can no longer get the poker rate for the WPT event in Biloxi at the Beau for the Labor Day weekend at least, it's going to cost you less to go to the Tunica WSOP Circuit event.
Rooms in Biloxi, will cost you an arm and a leg (and your firstborn) to stay there right at the casino, if you plan on going labor day weekend.
For me, it was also cheaper airfare wise to fly into Memphis (the nearest airport) from Denver (currently Northwest Airlines has a rate of about $260 RT for direct flights between Denver and Memphis), for the Tunica WSOP event, as apposed to taking a connecting flight to Gulfport.
All in all, I'm finding it very +EV to goto the WSOP Circuit event in Tunica, and -EV for the WPT event in Biloxi.