I also use the Katadyn Hiker when going with groups. It works very well and I have never gotten sick using it.
Solo, I use the Sawyer filter in a bottle. I purchased it at Walmart and transferred the filter and cap to a white Nalgene bottle as it saves weight. You could probably use a Nalgene softside also. I like this set up because I only need to carry one liter most places and can fill up a partially full bottle anytime I cross a stream without having to dig the filter out of my pack or wait for chemicals to work.