As a commentator on FML from pretty much the beginning, there have been certain features I've been waiting to be added for a long time, but which have never emerged, chief among them being able to hide long comment threads, especially when the contents are often completely irrelevant to the original comment. This kind of thread-jacking happens far too often on FML these days.
Being able to have comments made by your favourite commentators is also very useful for quickly picking out those comments likely to be of special interest to me. I also have no complaint regarding the new private message alert feature, as it's all-too-common not to notice the existing alert.
Each of the features can be toggled on or off too, if you're willing to perform a simple edit or two in the script's code.
So in conclusion, this is a great script that functions without any problems, and which I hope sees continued development and additions!