I have the katyden.the ergonomics are at times frustrating,but it works.The price has stabilized at $200.There was a price war and units were at $150 for a while.I've tried a friends PUR Explorer which is just about at your price ceiling.I like it very much.With 4 adults and 3 children capacity is a criterion,and since this will be a base or truck unit the weight is of less concern.Palatability may be an issue,especially with children,so a few packets of Tang or Koolaid are a good idea.I always have a serving of cultured yogurt before any preplanned adventure.A healthy gut flora will help you handle all the unseen environmental changes that can add up to distress.Don't forget that brushing teeth require purified water also.<br><br>