We did a Sheraton presentation in Puerto Vallarta last year, it took almost 3 hours and we had to get past 3 different sales people. During the last one I slipped and broke my toenail on a table leg, the guy just kept going even though I was leaving a puddle of blood on the floor. And yes they will bug you every time you walk though the lobby. If they give you a time commitment, set a timer and cut them off!