Since most of my touring is done on roads and near enough to decent water I am not super worried. Though if I were to get a filter it would either be a Platypus Gravity Works filter (for larger groups or more water) or a Katadyn Hiker pro. I have carried tablets for extreme extreme emergencies but I would try to avoid using them. I would also avoid some of the lightweight or less durable designs, stick with good proven technology and companies that put out a quality product and stand behind it.

The C&O canal water isn't the greatest but the iodine taste is very very weak and I haven't gotten sick but then again I try to build up some immunity and I happily drink tap water in most places.

Check your equipment well before your tour and store it properly. You never want to find out something just isn't cutting the mustard while out(unless it is a mustard cutter, then you are fine). Don't think because it worked fine on the last tour that things are the same.