Polak187, I have the Steripen Adventure and love it, you do need to get extra batteries for it when traveling so you can solar charge one set while the others are ready to use. If you leave the batteries in the unit while in storage, they will drain faster. I leave them out of the unit until I need them. I have yet to need to replace the rechargeable batteries that often if you keep then out of the unit. Several days of use. I thought about the Miox but on another forum from Alaska but they have had failures of the circuitry at altitude. The steripen has had the same with earlier models, I think now both are great units where the bugs are being worked out, Steripens weakness is the UV bulb which has a certain number of hours.
We use UV at work and I'm a big fan of UV, I will boil my water as a back up in a failure.