This is the sort of tool which you don't need very often, but when you do it'll take a job that's simply impossible and turn it into 5 seconds worth of work. Nice balance and easy to use. Do yourself a favor and spend the twenty bucks on a set of metric impact sockets - they'll keep you from ruining your regular sockets.
I bought these at hf when I bought my wrench http://t.harborfreight.com/10-piece-12-torue-limiting-extension-bar-set-69870.html , bit more pricey but with a 20% voucher too not much more than individual.
It doesn't matter, just as in my "nail banging" analogy it does not matter how many times you bang the nail--or for that matter how big a hammer you use--it will only go in so far.The torque sticks must rely on some industry standard for number of blows per revolution of the impact wrench?
Just for argues sake, let's say we have an impact wrench that does 3 strikes per revolution versus one that does 6 strikes per revolution.
The former would be able to twist the torque stick further than the latter, thereby applying more torque