First, I don't see how this thing could be a real HEPA compliant filter. My other HEPA filters are as thick as my whole Roomba and this thing's less than 1 cm thick.
My Roomba 530 Pet Series (I think that's right. It's a white one) definitely picks up less big stuff with these filters than it does with its iRobot AeroVac bin. I say this b/c it took a few runs to get some crushed leaves off the floor by the front door. That would make sense if Roomba has to force air through a more restrictive filter, which should be what this is. I hope that it's picking up more tiny particles and keeping them out of the air as the trade off. It hasn't been enough to noticeably help my wife's allergies though and I've been running the Roomba 2-3 times a day for about a month now. (there's also 2 HEPA filters going, an air ionizer, and the house HVAC unit his its fan pulling air through its filter 24/7 too)
My attitude is that this is worth a shot. So far it hasn't yielded noticeable results, but I'm going to keep running the Roomba with these filters hoping that it's making a little difference.
A note on cleaning: this takes a tiny bit more effort to clean than the AeroVac bin. There are 2 compartments, one main one for the big debris and a sealed one you have to swing open and clean the "HEPA pre filter". And the bristle brush seems to need cleaning a bit more often with this filter.
Normally I empty the bin and clean the filter about every 2-3 runs. That's about as often as I was doing it with the AeroVac bin, maybe a little more frequently, especially when I first made the switch.