I have a set of the Hankook Ventus V12s on my Mazdaspeed 3 that have just worn down to 2/32. I checked my order history and I've had them for almost exactly 2 1/2 (two and a half) years. This is on a car that I use every day for everything, including a half hour work commute (in each direction). I don't do any track days or any type of racing. I just wanted to primarily give others an indication of the tread life. It's on the short side, in my opinion.
As for my impressions of these tires... My original equipment was the Bridgestone RE050A that came with the vehicle. The Ventus V12s were notably cheaper. They are also more for summer and dry conditions. I found slightly more road noise with the Hankooks. I also found them to be more grippy around the corners, and I think they're easier to launch with as well, with less wheel hop / fuss (my car is front wheel drive).
I was pretty happy with these tires. I want to mention again, that while tread life might be relatively short, you really can't beat the price of these. I was happy with performance and grip.