Our Summary and Conclusion
Not everyone has the funds to drop hundreds of dollars on a new GPU every generation, but they may still want to improve or update their systems in some way. This effort was similar to going from a stock CPU cooler to a high-end aftermarket heatsink from another vendor. You kind of expect some thermal and acoustic improvements, and you typically get them. The cost of doing this on a GPU is basically two unusable slots, because the new heat sink and fans take up so much room, and the price of the cooler. But the upside is cooler and quieter operation, and potentially higher overclocks (or higher sustained Turbo/Boost frequencies), which would improve performance too.
The Accelero Twin Turbo III is certainly a much more powerful cooler that can dissipate much more heat than the stock GTX 670 cooler and its fans are quieter and move more air too. In that regard, it's similar to my new GeForce GTX 970 card, where the fans don't kick in until the GPU hits 60'C.
If you are adventurous, and can find your way around the poor documentation, the Twin Turbo III is a nice alternative to the roar of the 670's stock cooler and it'll fit a large number of graphics cards. Should you not have the budget for a new GPU, but want to quiet your existing one down and potentially squeeze more performance from it with some overclocking, upgrading the card with a powerful aftermarket cooler, may be a relatively affordable way to do it.