OPR used to have all cash buyin tourneys, but now, no. Tourneys with less than 30 people are not tracked. Most private MTTs are not recorded, and they don't track SNGs any more at FT either. So its informational value has diminished a good deal. But if you only play official $$ PS or FT or Ongame or Party, your stats will normally be fairly accurate. It is useful for ballpark figures. If you are checking out someone else, it can provide some sense of how successful they are at MTTs.
FT has tournament history, which shows all the tourneys, of all sorts, that you have played in the past week only.