I've seen and heard a Dumble (OverDrive Special ) in person - not a live show of a big name guitarist . Friend of a friend in San Jose CA. I was not invited to play through it. He plays good and has a successful band in the Bay Area. He uses Mesa Boogies live. I have also been to a few Robben Ford and Larry Carlton's show when they were using their Dumble amps. I have played the different clones like Fuchs, TwoRock, Ceriatone and Amplified Nation (I bought one but sold it)
The one aspect about the ODS clones is that they respond to volume from the knob position and your picking dynamics - notes bloom. I personally prefer Mesa Boogie's Mark which is also in the same camp. Larry and Robben sound like themselves with Fender HotRods, Fender Deluxes or Mesa Boogies. But something sweet about solo notes on Dumble. My original Dumble demo was short so can't really comment on it. It wasn't the voice of an angel for sure.
Not sure how it could compare to the clones, but the owner said that TwoRocks and Fuchs come close. Ceriatone and Amplified Nation at that time 6 years ago were the budget one's. Amplified Nation is a great shop to deal with. Ceriatone is made in Malaysia but he uses top shelf parts also great to deal with but they just don't specialize on Dumble style. At that time, Amplified Nation were just doing Dumble style amps. I am pretty sure the TwoRock, Amplified Nation and Ceriatone were handwired, no PCB but I think the Fuchs is. I don't believe in that crap handwired is better. Fuchs and TwoRocks are expensive. Fuchs repaired many Dumbles.
I heard that Larry Carlton cannot even make Alexander Dumble make another one for him as well as Santana. That is why they are now using Bludotone (from Colorado - expensive and multi year wait). I also heard he is from a rich family and does not really need to make money making amps. Go to TGP forum for info and drama - more drama than info on Dumble.