*Updated from a 1-star review*
The beta algorithm takes the gesture detection accuracy back to 98-99%. I've tried it out a bit and it detects everything correctly even if they're really sloppily drawn. Kudos to the developer for fixing it all in less than a week. Maybe in time the new algorithm (strict) will get more refined and I'll switch to it as well.

For a more general review, this add-on is simply amazing. Once you get used to the gestures they'll get your productivity through the roof (and you'll start to miss them in other browsers...)