Rated 3 out of 5 stars

The addon would be better if could actually implement this better functionality:

http://img833.imageshack.us/img833/4386/dualview.jpg (a proper secondary tab bar! for the 2nd panel split)

screenshot explains all. Splitting more than twice is almost never done, though its a nice added novelty, but the actual workflow and tab logic on it is completely illogical and could be improved. Try Maxthon 2/3 for a better tab splitting demonstration.