Rated 5 out of 5 stars

You have many options, but missing something vital. You need to put in an option that says do not zoom UNLESS you press a hotkey / shift key. And once you hit the hotkey, and/or shift key it will open up immediately. The time limit you have on is ok to anyone who just wants to hover their mouse, but if you're in a picture rich environment, and you hit the time limit it opens up. I would set the time limit bigger, but if I do, even if I hit the shift key I would have to wait 1-5 seconds for it open because it's still following the time delay. Please put in an additional option to only open if we hit a key, and once we do, it should open immediately. After that I'll rate this a 5.

UPDATE:
Thanks for responding. I didn't know I had to hold the key down before I entered the picture. I was always clicking the display key while I was over it. Now I understand, and I love it. And with the extra option of maximizing the image with another key, it's perfect! Thanks again for the help. I raised my rating to 5!

This review is for a previous version of the add-on (3.2.1-signed). 

Go into Thumbnail Zoom Plus preferences. Set "Key to" to "display" and set the key to SHIFT, CTRL, ALT, or Right Mouse Button. Then pop-ups will appear only if that key is down when the mouse enters the thumbnail.