I call him Rossi's brother cause they kinda look the same at one point (back when Simoncelli has slightly shorter hair and Rossi was doing his big hairdo). They even share a couple notable traits when it comes to competing: be brave, push the limits.
Yet IMHO a stark difference between these two riders is the fact that one is calculative, the younger one relies a lot on luck and faith. OK, it's not like Rossi has not crashed before. All of them do. Him, Simoncelli, Stoner, Hayden, Edwards, Pedrosa (oh who could forgot this year's incident that got some folks riled up when only Simoncelli was penalised... but I wouldn't go out to defend his "dangerous manouvre" either cause I'm not a rider, let alone a pro one)... who am I to judge?
All things aside, Simoncelli is a great rider. I mean, was.
Rest in peace.
p/s: A colleague of mine started a conversation about how the world is getting more grim, and the grim reaper is bla bla bla... (I was mentally blocking my ears and singing the Sesame Street theme song by then)...