Rated 5 out of 5 stars
This addon is one of reasons I can't migrate to web-based Google Calendar. It makes things so much easier!
Presentation (functional looks) is better than most I've seen:
* days are in lines (left to right), rather than in columns. This is good because you read left to right, top to bottom, not up-down, then left-right as in some. Also, screen has bigger width than height, and this translates to more days vs fewer months.
* weekdays correlate between months: first saturday of each month is single column. It would be great if I could select the week day to sync months on it, but even now it's ok.