I carried the Hyperflow for the entirety of my 2008 PCT thru-hike. By cutting down the inlet hose and ditching the bag and all the other crap they send you I got the weight down to 7.1 oz. The outlet fits platy bladders fine. This is less than any other pump action filter I know of (ie. not gravity filters). One of the main reasons I go into the b/c is for the beautiful tasting water, so pumping was worth it for me...YMMV.
The filter clearly states that it will clog on very cloudy water- I would not carry a .9 oz/yd silnylon shelter into a gale and ptich it on a ridge. Lightweight gear has limitations, that's the deal.
All of the reviewers comments are true...the valves will collapse under high pressure, backflushing only moderately restores flow, prefilter flips over, filter life is substantially shorter than other filters (I used a total of three in 125 days of hiking, although after leaving one in a motel in mojave, the replacement had the defect in being unable to unscrew the pump handle described by the reviewers, and was replaced by MSR, so I was unable to backflush, so really more like 2.5).
I carried bleach in a microdropper when I didn't feel like pumping. I knew there was an abundance of clear water on the PCT- I filter almost everything (I got food poisoning while solo once and don't want to ever be weakened in the woods again). I HAVE NO INTENTION OF CARRYING THIS PUMP ON THE CDT. This pump was definitely overhyped, but every design requires many iterations of improvement. I may carry this punp again- it does weigh 30%+ less than the Katadyn or other pumps, but plan to replace the element more frequently. HYOH, YMMV.