love it so far
I am really happy with my purifier so far. I have not tried scooping water from a stream, so I can't truly comment on the Virustat cartrtidge yet (and therefore can't give it 5 stars). I have used it for travel to places with "safe" water, but I used the pre-filter just to get rid of unpleasant tastes. My bottle seals securely and I have not had any problems with leaks while putting it in a bag in the car or on an airplane. It fits nicely in my hand as I jog and does have an integrated loop to clip on a bag. I've seen other reviews who thought that it was too difficult to squeeze out the water, but I haven't had a problem, although I've only used the pre-filter on a regular basis. In my trials of the complete 3 stage system, I didn't think I had to work excessively to get the water out. The only think I don't like is that there is no cover on the spout, so it could easily be splashed with "tainted" water or mud or whatever. I think it needs some type of shower-cap to keep it clean. Also, my kids are always trying to take it and flip the spout open and closed. This unit is light and easy to carry even when full, although it is only 750 ml or 24 oz. (but the whole point of the unit is that you can fill it frequently and not carry gallons of water).