I have broken 2 sets of bolt extractors on alltrac bolts. I have given up on them. This might work on screws, I am not sure about alltrac bolts. I am going to attempt to drill the bastards out.
It will work in some cases but you really get what you pay for when it comes to tools. If you want quality get a reverse drill bit and extractor set from a Snap-On distributor and a good air drill to use them with. There is no replacement for quality tools in my experience.