Did it in Sept 2011, the bad tar downgrades it to a three star rating.
From Stadl take the turn off BS97 in the town and head southeast towards the Flattnitz ski resort. The road is well surfaced and has a few interesting bends. I've done it twice in 1993 and 1999 both times on a GT750 'Kettle', so it was more of a fight for me than it would on a modern superbike or my current BMW GS! You can lunch at the Flattnitz resort before continuing southwards into Carinthia.