Rated 2 out of 5 stars
It works very well, however it does not imitate Safari's feature.
In Safari you do not have to manually save a URL for Snapback:
"The way Safari's SnapBack works is by silently marking a web page every time you type in a new URL, click a bookmark, or open a new window."
(In Safari you still can create a SnapBack point by going to History > Mark Page for SnapBack in the menu bar.)