Rated 2 out of 5 stars
The service and add-on themselves are fairly nice, with some occasional flaws where Firefox (with some help from Greasemonkey) is actually better at form detection. Unfortunately, LastPass are not, apparently, bothering to keep the AMO release up-to-date.
Half marks, rounding down.
Submitted update to AMO
FWIW, we submitted an update 2 weeks ago to AMO. We are still waiting for them to approve it.