I have used the miox for leading groups of up to 10 people and it works fine for me. I have sent other groups out in my program though and the trip leaders hated it. They've had problems with batteries, not getting the strips to turn purple, and problems with salt levels. I've used a Miox for over 10 days and haven't had the problems they've had. It tastes better than Iodine and is simpler than aqua miura. Use a bandana for floaties and sinkies, or Steri pen makes an amazing prefilter that screws onto a nalgene bottle and filters out all particulate matter (in my experience) your mileage may vary so I give it 4 out of 5

I don't own one yet, but I've played around with it plenty.

To comment on the comments provided by ScubaSnyder:
A very useful, cheap, lightweight, and foolproof method of removing dirt from your water involves 1 cotton bandana and a little bit of inginuity.

This is a great water filter, it kills viruses unlike other filters. The only drawback tothe use of this water filter is it does not remove particles of dirt. I recomend another water filter with this one for the cleanest water. Also with this filter its basically fullproof unless the batteries die, it has led lights that tell you if your battery is low or the amount of salt is low. Also the filter comes with 50 test strips that tell you if the water is ok to drink.

This is so far the best water purifier I have ever used. After using this little 8oz wonder on a six day trip, I don’t think my PUR will ever see use again. It is so light I take it on day hikes, and forget its in my pack. I have had the pleasure of using the big industrial units, luging big bags of salt around and getting confused by the PLC readout, but this is much better no confusion here.