After much deliberation, I finally picked up one of these babies last night. In my opinion, water treatment is a fairly significant issue for this race. Last year I used chlorine type drops (which was a pain) and I did end up getting giardia which is always sweet. I have talked to other racers that ditch any sort of thing like this and use drops to save weight but I think it's worth carrying. I know others that use a Steri Pen but I just wasn't diggin' it as much. Pictured, this thing is 14oz (but I only need to bring the actual pump/filter, hose, and drops) and I don't have to remove the bladder from the pack anymore which is a small thing but it sucked. I also have significantly decreased the size of my cooking kit. I'll take pics of all this stuff that's going this year. I'm embarassed to say that I will be probably almost 15lbs. lighter this year (not me...although I have lost 10lbs but I'm just talkin' bout gear). I learned a lot last year.
This was the alternative to getting a reliable purification system and just sticking with the drops but, for the life of me, I just couldn't figure out how to pack it and I looked like a damn fool with it hanging around my neck.