I have only been to the stages (which is something I highly recommend)... I am not so much of a start struck person and most of the people competing were active before I was born so... even if I was star struck I don't have that much connection with almost any of the drivers.
The machinery though, that's something you can appreciate for sure! Bring ear plugs! ...and visit San Marino the city while you are there, it is very intesresting :)