As for so called Montezuma's Revenge, well I always eat the local food when on holiday and I never have any problems. Perhaps I just have a strong constitution of course.
This was my fifth holiday this year including Iceland, Cape Verde, Rhodes and New York. Now planning next years.
Many Mexicans still use motorbikes to commute to work, but they are mostly Chinese clones of the Honda/Suzuki 125's. The police use Harleys which are polished up just like show bikes. The Federales use KTM trail bikes for rapid response for their machine gun carrying chaps.
I found Mexico to be a wonderful place, but with a distinct lack of larger capacity bikes. Might even go back next year.