Never owned or used one of the SkyThumper mics. However, a local friend of mine uses either the SkyThumper, a
RoadKing 56, or an
Astatic D104 in his mobile station. I can tell when the ST is being used. The sound that I hear out of my end of the radio is a mic that is modulating the crap out of the radio he is using. It is probably the loudest noise-cancelling mic I have ever heard - IMO. Louder than the RK 56 without any doubt.
I am not the guy that uses noise cancelling mics. I don't drive a truck. I drive a late model Honda CR-V which is a pretty quiet ride. I use a
RF Limited CR-577 mic; which is a mix of a power mic like the D104 and a RoadKing 56. It works best when I keep it close to my mouth - unlike a D104 that can be used up to a couple of feet away. But the frequency response of the 577 is better than the D104 and doesn't have the noise problems it has.
I have owned and used a RoadKing 56, and so has my friend. These mics have a fuller frequency response than the ST. The ST response is pretty narrow but very powerful. If I had to chose between a ST and a RoadKing 56; I would pick the RK. The difference is really in the price you pay for either mic. I think that if you make a living at driving; then I would go with the RK. Perhaps the ST as a backup. The ST isn't a bad mic at all. The RK is a classic and probably the most sought after and used noise-cancelling mic from what I hear from truck drivers. You can do better with the RK that the ST is all.
This isn't a review but an observation based entirely on what I have heard for myself. The ST is far cheaper than the RK. Depends on how much quality you need to do your job - I guess . . .
Don't like the sound of a 636 or a RoadDevil either - JMO. I would pick the ST over those two mics - any day.
SkyThumper Microphone