Well the reason why I like the steripen Mark is:

1.Filters are to big and bulky to carry plus weight and there are only a very few of those that are purifiers and general ecology is one. Steripen is a purifier killing over 99.9% of bacteria, viruses and protozoa and has been field proven. It has had it's quarks like most everything in early development and that most problems have been worked out. Even reviews of the general Ecology have had issues of excessive clogging up in the field. Pumps are mechanical with o-rings and moving parts which are prone for failure.

2.The tablets, whether it is microPur or what have you are small and effective but it takes 4 hours of waiting before you are truly are purified and you have to carry a lot of tablets for long stays (figure 4 tablets a day minimum).

3.Boiling water takes fuel, whether it is firewood, gas or what have you, then you have to let your water cool down before you drink it. You may need that firewood to keep you warm as well though you could boil while you warm up but I don't want to stop and boil water every time I get thirsty. Try that when you pass through a town in Mexico or south America.

4. Dip in go bottles take time for the water to fill the bottle through the filter, they offer small amounts of water per size and are limited to a smaller amount of gallons requiring changing out more frequent than pumps.

5. Miox is not a bad idea but leaves a chlorine taste in the mouth and requires you to carry salt and test strips.

6. UV (steripen and others) used by Nasa, weakness is bulb life but the steripen has a 2113 gallon (8000 liters) lamp life and is a very rugged lamp and I have drooped checked mine. The water has to be relatively clear which can be done with a banana or skim the water off the top. It takes 90 seconds and I have water that is purified and in a space of my pocket weighing in at 3.6 oz. I do carry micropur tablets as backups but haven't had to use them yet. It can be ran off of solar cells with no battery in the unit and now a handcrank with no sun.

In conclusion the best purifier I have found for my use is the steripen (which I have tablets, combi filter, desalinators, etc...)due to the size, weight, functionality,durability, and speed, because I am a very heavy water drinker and consume lots of water, this is a big time saver for me. Everyone has there way of doing things and what may be tried and true for you may not have worked very efficient with me or vice a versa. I like keeping it as simple as I can for what I need, my steripen has worked flawlessly in south america, asia and europe as well as north america and I haven't got sick yet, not in mexico, Philippines, costa rico, etc..