Well, I originally bought my Wee as a winter bike for commuting but after a couple of short trips Mrs Iggy reckoned it to be the most comfy bike I've got.
Since then we've done around 11k miles on five decent trips on the Continent. We tend to toodle about on the smaller roads most of the time, but the bike can cope with pretty much anything and got us back from Barcelona in two 500+ mile days a few years ago. Its stable at an indicated 110 fully loaded too.
As has been mentioned, its worth beefing up the suspension at both ends and I have also improved the brakes and got a better seat among other things.
I sometimes miss the oomph of a bigger engine for easy overtakes and the engine needs working quite hard in the mountains - mine used about half a litre of oil on the most recent trip too. The balance and handling of the bike is also compromised somewhat when fully loaded (though maybe we just take too much junk) which annoys me more than a lack of power.
However, on the plus side, it'll do an easy 250 miles on a tank (we've managed over 280 when taking things slower) and tyres last a couple of trips plus the riding at home in-between. There's also the feeling that with it being a cheap bike and not too precious I don't worry too much about where I park it and will happily take it places I might hesitate on something flashier.…...
Touring is more mind-set than machine. Pick some nice roads and go have some fun !
Iggy