He believes more southern European grape varieties are better suited to the Australian climate, but he makes Shiraz and Grenache as well. He likes to keep alcohol levels low. He appears to be non interventionist in his winemaking to the extreme.
The result of this is, in my humble opinion, that a number of his wines taste like juice, some really sweet and juicy. The 2010 whites, Sauvignon Blanc and Pronto Bianco, are pretty, but don't leave a lasting impression.
The 2008 Pronto Tinto, a Grenache dominated blend, the 2007 Tempranillo Touriga and the 2008 Nebbiolo have simply not reached the potential of these grapes.
This takes me to a comment about alternative varieties. It is one thing to say they are better suited to the Australian climate, but quite another to produce wine which equals those produced from these grapes in Europe. I have tasted good examples of Sangiovese here, for example from Pizzini and Castagna, but our Tempranillos and Nebbiolos in particular, do not come close to an average example of such a wine from Spain and Italy.
The best Pannell wines were the 2007 Grenache/Shiraz, and the 2006 Shiraz. The latter in particular is very good. From old vines, it tastes of blueberry, blackberry and chocolate. It is a concentrated, yet elegant wine with a long finish.
So overall, educational, but a mixed experience.