It seems the steripen is similiar to the miox, except it says it will kill the crypto in 60 seconds instead of 4 hours that miox says. It also uses 123 batteries. Has anyone used the steripen?
Steripen uses light waves to render the bugs "sterile", while miox makes a solution through electrolyisis to kill the nasties.
Here is a comparison I found where the marketing manager from MSR, Katie Bolek, on the comments section of a review.
"I'd say the biggest disadvantage to the Steri-Pen in contrast to the MSR MIOX Purifier is its inability to treat water with particulate material, although the Steri-Pen functions fine in clear water. Note that the Steri-Pen was unable to pass the EPA Purifier Protocol in "Type II" cloudy water. Even minute material can impact its effectiveness, so the water basically has to be filtered before it can be treated with the Steri-Pen, requiring the use of a second treatment device. The MSR MIOX Purifier, on the other hand, is more versatile, because it is equally effective in any type of water, including a cloudier water source, and pre-filtration is not required.
Interestingly, UV works quite well against "resistant" organisms, like Cryptosporidium and Giardia, but it is not able to inactivate certain viruses, like the Adenovirus. (Viruses tend to be more of an issue in standing water than in running water.) Again, the MIOX Purifier offers more versatility than the Steri-Pen because it inactivates ALL classes of microorganisms.
In contrast, probably the biggest advantage to the Steri-Pen is that it is a more rapid process (1-1/2 minutes) to inactivate Giardia in 1/2 liter of water than required with the Purifier (30 minutes). The wait period is virtually the same for the more common bacteria and viruses -- 1-1/2 minutes for the Steri-Pen and under 5 minutes for the MIOX Purifier (based on the most recent round of third party testing).
Another factor to consider is the size of the treatment device. The Steri-Pen is much smaller and lighter than a handheld filtration pump, but it's still about twice as big and twice as heavy as the MIOX Purifier.
Also, the Steri-Pen is not designed to treat varying volumes of water. With one dose, the MIOX Purifier can treat a 1/2 liter bottle of water, a 2 liter CamelBak hydration bag, or a gallon jug -- this versatility is nice with a larger group of campers. Also, you can treat multiple quantities, wait the specified time, and have all of your containers of water ready to go at the same time with very little effort.
One last item I haven't mentioned yet is that the inclusion of the test strips enables the user of the MIOX Purifier to ensure that his water is safe to drink. Measuring a certain amount of residual disinfectant in the water shows that there is sufficient disinfectant to inactivate the microorganisms. In contrast, no other technology comes with the safety indicator strips. With other chemical disinfectants, if you're consuming water potentially contaminated by sewage flow, you have no idea if 2 tablets are going to be enough, or if you need more than 2 tablets. With the Steri-Pen you can't tell if you got all the microorganisms, or if one of them was hiding behind a particle in the water, thus making it unsafe to drink. Use of the safety indicator strips with the MIOX Purifier just gives an extra measure of security to the user, especially if he or she is drinking from a source that is potentially highly contaminated.
In summary, the MIOX Purifier is just a more versatile tool since it can treat clear or cloudy water, treats a wider range of microorganisms, is smaller and lighter, is configured to treat various volumes of water, and can ensure that the water is safe to drink. I haven't found the 30-minute wait time to be an issue because I always have multiple containers of water I'm drinking, so I have something immediately available. It usually takes me at least 30 minutes to accomplish whatever other task I'm doing while camping (or I'll treat the next day's water before going to bed), so I tend to not even notice the wait time required.
Hope this information helps!
Katie"
Also, I saw the vario, but I used a msr miniworks ex before, very similer system and it was way too slow for my tastes.