thanks to you for responding! I dont see myself taking any extended backcountry trips alone - there is usually at least 1 other if not several fellow hikers/paddlers with me. For this reason (and the aforementioned laziness) i have been leaning towards the gravity fed systems. Perhaps I will end up getting a Sawyer for the smaller, solo trips and have the platypus for the bigger trips. Either way, thanks for the help.