I will travel on a round-the-world ticket starting in July this year, and in my flight schedule I have included trips to both Shanghai and Dubai. I am planning to adjust my schedule in a way that I will be able to attend either the Shanghai GP or the Bahrain GP in 2010, but not both (as they will probably be held on consecutive weekends).

The question is, when all other touristy activities are set aside (say I will visit both places anyway), which GP should I choose?

I think Shanghai would be a safer choice. The racing is usually a little bit more exciting there.

we always sit as high up in the main grandstand. this way you can see over the top of the pits and paddock and you can see all over the back of the track.
you can also walk thru all the other area's and even sit in the other grandstands if you want during the practices etc. so it's great to see all the other corners up close.
have done bahrain also. can't see the back of the track though there even high up as the grandstand on the back straight is in the way. still bahrain was very exciting and different too experience culturally also.
would still go back to bahrain again.