At a minimum, I would take my own reg set, mask and computer. Maybe my own wetsuit if i knew the water was going to be cold. If my plan was to dive in more advanced locations ( for example; Cozumel ) I
would bring all of my own gear. Often, the rental gear is used six days a week, sometimes twice a day. Sometimes, problems with this gear go undetected until its too late. I am more relaxed and have more fun when using my own gear.