"Great when it's working; might sometimes be finicky and it's always VERY fragile"
Sad things first. I broke mine by dropping it on the floor. The plastic cap was on but the shock is enough to make the internal lamp crack. that's why the company sells more expensive Classic and Travel models: they include a somewhat bulky neoprene case. So if you decide to save some money by buying this less expensive model, get a good case for it.For batteries I used NiMH Eneloops, great battery life but heavy.Probably not great for backpacking, but for 'urban' travel in areas with dubious water quality it's quite good. A great conversation starter. When you are shaking a bottle glowing with menacing blue light, everybody is watching you and wants to know what's this all about:)
"Same as every other SteriPen, but cheaper!"
The SteriPen "Emergency" model is marketed for home emergency preparedness kits, and is about $20 less than every other model. I called SteriPen directly, and confirmed that this is the EXACT same as the Classic model, just in a different color.The UV purification has never failed me. I've purified water from lakes, rivers, streams, and ponds, all with a variety of fish/birds/deer/Sasquatches living in them, and I have never gotten sick when drinking the water. The only negative is that this thing eats up batteries like I've never seen. It could be that my batteries aren't happy in the cold, but even so, I need to carry lots of extras with me when I hike, and batteries are heavy.