
Using an iodine-based filter doesn't get you past the issue of ingesting iodine for a long duration, if that's a problem. I can't see any advantage of filters over iodine treatment on its own (in the regions you indicate, anyway) other than better-tasting water. And they're just more expense and weight.
Whenever you're in hotels/hostels or on portered treks, you'll be able to get boiled water, and in Aus/NZ the water supply is safe. And if you're camping, you'll need a stove, so boiling will be as easy as anything else. I'm guessing that as long as not ALL your water intake is iodised, any side-effects will be proportionately reduced.
I've never owned a filter - always used boiling or iodine drops - and never had any problems. Not that I've done it for a year at a time. If you don't like the taste of iodine, PSP22 and some other powdered drinks cover it well.