Rated 4 out of 5 stars

i will give 5 star if it support preload larger images on websites. Just like Hover Zoom for Google Chrome.

This review is for a previous version of the add-on (1.6.0.1-signed). 

Thanks for your suggestion; I've added it to our issue tracker here: https://github.com/dadler/thumbnail-zoom/issues/53 .
I may add it to a future release, but it'll take some work to implement. It would also use more network bandwidth, which might be a concern to people with data usage caps.