Before taking decision to buy MacBook Pro I was browsing forums to get familiar of what shell I expect from this piece of HiTech.
Moustly I get the message that MBP is getting quite hot. The reason for this was named that manufacturer have defined big treshold before fan starting works. To adjust this was recomended to use Fan Control.
I would say that this is moustly true if you are loading your Mac quite highly. In case you are doing some web surfing or documents/spreadsheets editing it is Ok to use default manufacturer settings.
Please keep in mind that Fan eats you battery :)
In general Fan Control is small, nice and working software. If you know what you are doing you'll find it really usefull.

Regards,
Sergey