Nice Chris, good to see your getting stuck into them, I'll wait for the same 2 AJ variants you've noted above (oiler and OPC) to arrive before test driving any of the new Opels...
Still can't get over how 'booffy' the new Astra is, as you have noticed the wheel arch openings are gigantic, it still looks SUV-ish to me I reckon you could get 24" rims with low profile tyres to fit in there lol
Also I'm not surprised to hear the ride quality is good, the stock wheels on the GTC are fitted with massive 50 series rubber 235 wide tyres which should cushion any bumps...
Oh forgot to mention I got the suburb wrong, it's Sth. Yarra lol was thinking of 2 things at once when I wrote the previous post, my missus also manages some shifts in a priceline pharmacy in Caulfield as well as the one across the road from the new Opel showroom in Sth. Yarra