My instinctive reaction, as an amateur, is that this is segregating and not needed. If you want a label that indicates whether something has a pro version, fine, but I can find that for myself by reading the details. I am much more interested in solving a particular task when I look for a plug-in, and generally start with a free version, adding the pro version if I find that what it offers is important to me (generally not, as my sites are small and for low-budget grassroots groups). I guess some folks will find the filter useful, but I really don’t see it.