I go to sharkscope every few days . Its good for checking MTT results of your opponents . I think the rebuy + addon events don't get tracked too accurately so you have to be aware of that . Even so info like 'average field beaten' and 'itm ' percentages , as well as 'roi ' and 'average buy in' can be quite useful !
I check sharkscope if I'm deep in a tournament and have been sitting with same (usually aggressive) opponent for a while. I think it gives me a slight edge to know how profitable/experienced he is. I usually know when I am versus a more experienced player by their bet sizings and aggression, but sharkscope helps confirm it.