In reply to thelostjockey:
I've done the Walkers Haute Route, Stubai Rucksack Route and the Zillertal Rucksack Route.
The Stubai and Zillertal ones were done with some 2 night stays at huts to do an off-route mountain.
They were both done at the beginning of September and I think the overall grade was about the same. One of the Zillertal days was longer than any of the Stubai days but not ridiculous.
For the Stubai we took axe & crampons, needed for some of our mountains. For the Zillertal we just took poles, sufficient for the mountains, although we would've checked first at the hut - but we were certainly ok for the trek.
Like the Stubai and unlike the Haute Route, once you climbed high at the beginning, you stayed high.
If you were happy with the Haute Route and Stubai, you'll find the Zillertal no worse - although obviously you can't guarantee the weather on any of them!
I still have my basic day-to-day plan showing the huts and the planned off-route mountains, so email me and I'll send it.