Borderlands 2 is too busy for 3D
3D Vision is pretty awesome with certified games though, adds a whole new depth to the experience. The kit is £50 but you know you will need a 3D Vision Ready monitor? (120hz capable). Unfortunately they are all TN panels, so although the monitors are cheap the colours and clarity could be better. I've had 3 of them in total (replaced by ASUS under warranty), all of which have developed dead pixels.
Also aim to buy the mk2 kit, as the mk1 glasses aren't as comfortable, and also don't have as wide a viewing angle. It can also make games very dark occasionally, and even the current gen screens suffer from ghosting (especially on white or bright areas) which is really noticeable.
People also moan that the batteries wear out too quickly, but it's where people leave the glasses on charge constantly I reckon. Admittedly I haven't really used mine in ages, but for the occasional single player game it makes all the difference