When it comes to oak barrels size does matter. The smaller and younger the barrel the more flavour it imparts to the wine. The older and larger barrels allow the wine to age without gaining any oak flavour effects. Both have there place in wine making.
According to our host at an Italian wine tasting the other day, the Italians apparently prefer to age their wine in the larger barrels in order to preserve the fruit flavours of the their grape varieties.