has anyone tried out these new water bottles with a filter in the cap? i've been looking at this one...<br><br>http://www.seychelle.com/<br><br>...but i'm not really sure about it. a guy on ebay that's selling these says that there are two types of filters out, a 3 stage 'normal' filter (2 micron absolute) and a 4 stage silver impregnated filter (an attempt to kill viruses?). there's a few others out there, but this one does far more water between filter changes (100-200 gallons) than the others i've seen (as low as 25 gallons, and with much bigger filters).<br><br>any thoughts? thanks.<br><br>