This three grape Rhone blend has become very popular over the last 10 years. Most of them originate from the Barossa Valley. I had an opportunity to compare three of them in the last couple of days.
First, I tried the 2004 Teusner Avatar. The fruit of this wine was very ripe and the taste was dominated by fruitcake and caramel. In my opinion, the grapes were picked too late and while I remember I enjoyed this wine a couple of years ago, it is not one for keeping.
The 2005 Teusner Avatar is the better wine: it is also dominated by the fruitiness of the Grenache, but the fruit has more vitality and is backed up by good (not great) structure. Fruitcake characters show up as well, but the wine is not overly sweet.
The 2004 Bin 138 Penfolds GMS has quite a different profile. It is a more restrained wine where savoury characters balance the fruit. In fact the fruit is a little thin and the back palate a bit weak. I don't know, but I suspect the Mouvedre component is quite large. This is quite different from the 2007 Bin 138, tried last week, which has quite strong upfront fruit, probably falling between the 04 Bin 138 and the lush Teusner wines.
In summary, you can get quite different outcomes from GSMs. In some, the Grenache fruit dominates and they are more short term 'barbeque' wines. Others emphesize savoury elements and structure (Melton's Nine Popes would be an outstanding example).