Healthsomeness released a comprehensive research article that tested the top 20 portable water filters for backpacking. Survivor Filter and Survivor Filter PRO both made the list and received very high reviews from the experts!
An Excerpt from Healthsomeness:
"A personal water filtration system or device is the best way to ensure that you have consistent access to clean drinking water whether you’re camping, hiking, traveling, or in any disaster or emergency situation. However, with more options available you’ll need to take some more time researching these products to identify the best one for you. This is why We’ve compiled the following reviews of the best water filters available on the market. The reviews include many different types of filter, from personal drinking straws, to gravity systems, to pump operated systems, tablets, and even water bottles."