From the Clare region, apparently these vines have a bit of a weird history, originally they were low yield dry grown Shiraz, and then turned into Chardonnay by grafting in 1980, and finally were turned back into Shiraz in 1996.
I empathise with those vines, having once been known to partake of a full bodied Aussie Chardy, I now find myself drinking Sparkling Shiraz much more often when needing a wine for warmer days.
Popping the cork made me very glad I had decided to hold onto it as the pressure was rather extreme, not only would it put someone's eye out, it'd probably knock their bloody head right off!
The fizz was too much initially, and I'm not sure if this is primed intentionally high or someone got carried away, but initial taste was just far too overwhelmed by the carbonation, leaving the wine very one dimensional and bland.
Let the fizz die a bit though and it's far more interesting. Not at all sweet, which is a huge bonus, and something the cheapies do so badly - trying to overcome carbonation bitterness with excess sweetness. Instead, with the Knappy (sorry, couldn't resist) we have a very more-ish wine with a nice balance of fruit and dryness. There's almost an oily texture that gives it an added complexity due the acid blending in well.
I think it's quite overpriced at $22 CD, but do some searching, perhaps on an auction site and you can probably find it for under $15 right now and it's good value then.