Hey, if somebody wanted to pay me to plug in an OBDII connector, I'd let them. And we know those people are out there. Their website is just marketing.
As for numbers, I don't expect them. This device is rather generic. They set it up with parameters to work with a lot of common vehicles. They may even test a little bit with each one, just to be sure it works. But, it works with a LOT of different cars! (it would work with not only my Mirage, but also my wife's Miata, and even my 1997 S10!) There's no way they're going to do before and after dyno testing on each one, or fuel economy testing before and after with each one. They just can't.
You just have to accept how the thing works. It's modifying things like fuel and spark trim tables. The ECU has a main fuel table (probably more than one for different conditions), and it has "trims" that are adjusted both short term and long term. This is how the ECU "learns". All it's doing is making the ECU "learn" a set of trims that meet your needs. If you want fuel economy, it's going to "trim" to not go as rich under load/acceleration. If you want power, it's going to trim for a little more fuel under acceleration, and advance the timing a little bit. You're going to run premium fuel? It's going to go just a little more advanced with the timing. Etc, etc.
As someone who's done some "garage level" tuning with fully programmable ECUs, I can tell you that what it's doing is exactly what I'd do as a starting point if I was tuning a car. I want more performance... I'm going to give it more timing advance. If I'm going to run premium to prevent pinging, I can advance it a little more. But, I know I'm not going to go to the expense of dyno tuning, so I'm going to keep those changes conservative. I know from experience that I can advance timing by 8-10 degrees without pinging when I'm running premium... so I advance it by 6 degrees to be safe. (our cars also have a knock sensor, so if there is any pinging, the ECU will detect it and dial the timing advance back) And if I've added a header and exhaust or intake mods, I know that the engine is going to be able to use a little more fuel to make more power with those mods, so I can add that.
That's all it's doing. Making educated "guesses" toward slight improvements to the factory tune within the ranges of the factory trim tables. It's possible that if you modded your car (or not) and drove it in the manner you wanted it to tune for CONSISTENTLY, that the ECU could eventually arrive at this set of trims on its own.
There's almost certainly not enough adjustment in those factory trims to allow for adding a turbo or anything like that. But, for minor mods, this device should work.
I don't expect anything magical from it. But, if it can give me a little more timing advance, and a little more fuel at the top end... that should result in performance gains that I can feel and probably measure. For $130... that's all I expect.