Quick and Easy
I used a MSR Hyperflow for a couple trips, but decided to try new technology after the Hyperflow became difficult to pump midway into a hike. I generally backpack in areas that have clear but microbially suspicious water, so UV seemed like a perfect solution. The Steripen Adventurer worked well on a recent trip in Utah canyon-country, keeping us healthy even after having to drink from stagnant pools that were very questionable looking. Keep in mind that this will not alter the taste of the water (for better or worse) like filters or chemicals will. UV also works best in clear(ish) water, so in areas with a lot of suspended sediment this might need to be coupled with a mechanical filter of some type. Overall an extremely effective and quick way to treat water.