I also use a Kathmandu shirt, but mine is a Nylon/poly mix.
The nylon makes it tough and less stinky, and the polyester manages the moisture (sort of)
It's really tough, to the point of ridiculous. I use it rogaining, including the World Champs in the Warrumbungles, which included a couple of hours of literally using bodyweight to smash through some old dry scrub, and a four day trip down the Lerderderg gorge, which is one way, due to the flood angled scrub.
I posted a thread about eighteen months ago, to ask how tough windshirts really were. From memory, I only got two answers from people who had actually managed to tear theirs. I don't think my Houdini is as tough as my Kathmandu, or anywhere near as breathable, but I think you'll work pretty hard to shred it unless you're on granite or in Tassie scrub.
Just remember that most users who are posting about how much they love their windshirts aren't walking in Aussie conditions. I'm guessing that most OS members would hesitate to go out overnighting when it's over 90F (32C) and many that do will head higher into the mountains than you or I can, where it's a lot cooler. A windshirt works great in those conditions.
Apart from that, welcome aboard, and feel free to post in the Aussie thread.