I have never once regretted buying "the best" when it comes to tools, but oh so often regretted buying the cheap stuff. Quality tools allow you to do quality work with the lowest frustration level. There is also quite a bit to be said about having the right tool for the job and that is often the only thing separating the pros from the weekend warrior. That being said...I've never tried one of these sonic buzz do-all thingies.
Mike
C227