I have been researching water filters and need some advice. I am taking a group of boy scouts (12) on a week long canoe trip on the lower portion of the buffal river in AR. It is a 53 mile trip with just a couple of public water sources along the way. In the troops gear we have several hand pumps filters(katadyne and msr). We have used these on weekend backpacking trips with no problems but I am looking for a better (FASTER) way. I have been looking at the sawyer 4L system and their point one bucket system as well as the katadyne base camp. I like the thought of the "bag" systems just for the fact they take up less space. What experience has anybody had with any of these systems.