Even a quest for the perfect wine needs a reality check. It’s a good idea to drink cheap wines, not only because they are cheap, but because they remind us of what most wine drinkers happily consume.
The Casillero del Diablo is made by the renowned, Chilean, high-production colossus Concha y Toro. Although they produce wines at every quality level, this is one of their value wines, widely available and much praised in the industry for its popularity. If you like this style of Cabernet this is surely a good value.
The nose is simple but pleasant. Black currant, coffee, and restrained toasty oak dominate. Their website claims 70% American oak which is unusual in a wine at this price. It thankfully lacks the puerile, candied fruitiness of many budget wines. It is a wine for adults, and the medium body, glassy texture promises some elegance. However, the palate exhibits a pronounced bitter, herbal note that is unpleasant and distracting. It mars the finish which cannot end quickly enough.
Chilean Cabernets tend to be less fruity, more herbal and with lighter body than American versions of the grape. This is a good example of the type, but there is not enough complexity or dimension to counter that wild, herbal tang.
As a sipping wine I can’t recommend it since I find the flavor profile unpleasant. But a juicy burger with the fat to neutralize the bitterness would pair well. I wouldn’t run away from this wine, but I would not seek it out.
Price is around $8.
Exploring the Philosophy of Food and Wine 
You were tasting the 2011? You should find a bottle and revisit that assessment here near the end of 2014. This is a value wine that can actually age well in bottle. When I put this wine up against some stiff competition with my tasting group – 2012 Educated Guess Cabernet from Roots Run Deep Winery and 2010 D’Arenberg High Trellis Cabernet (90+ points in most major publications) – it easily held its own, with a delightful blackberry and white pepper lingering finish. No bitterness, not even to the members who are very sensitive to such things.
I can only assume you tasted it too young or too cold. Many Chilean Cabernets are *not* balanced to be chilled. Serve them on the warm end of the recommended Cab serving temp scale: 65F-ish. If you chill them down to the traditional 62F, they can be too tannic – but I’ve found that to be true of almost all Chilean Cabs at many price points, not just this one.
Speaking personally, only that 2010 D’Arenberg is higher in my esteem and I regularly taste 1er Cru Bordeaux and $50+ Napa Cabs for my job. I work in wine retail, and I have routinely recommended both the 2011 and 2012 Casillero del Diablo Cabernets to customers who say they prefer restrained and balanced Cabs as the best deal in my store… even to customers who regularly buy in the $50-$90 range, and so far *every* one has come back to tell me how much they love this wine… and how shocked they were.