GMT, Brian Croser makes Sparkling for the cellar. I recently bought a bottle of the '92 Croser, which is about ready now. They often seem elegant, but a little simple in youth, but blossom with some age. Try an older bottle if you can find one.
Aussie: Will do, as soon as I find one. The Vintage Pirie was a disaster also. I am having second thoughts about down-under sparklers, but will try others. Any opinion on Deakins Estate sparklers?
Haven't tried or heard about Deakin Estate Sparkling, though I doubt they will be any good (their still wines are very pedestrian). Names to look out for that won't disappoint: Hardy's Arras, Domaine Chandon (based in the Yarra Valley - excellent blanc de blanc, prestige cuvee and cuvee riche), and occasionally Yarrabank. There is a lot of development going on in Tasmania with sparkling, and the next few years should see whether the effort was worthwhile.