Their baseline for a C63 S on a Dynojet in SAE correction is a bit low from what we have seen from other tuners. Only 438 wheel horsepower and 454 lb-ft of torque to the tires from the M177 4.0 liter V8 points to a very conservative Dynojet or perhaps a desire for exaggerated gains.
It is important to focus on the difference between the baseline and tuned figures though and not just the peak numbers. Velos shows gains of 71 whp and 90 lb-ft of wtq. Solid gains although less than what Eurocharged has hit and a bit less than Renntech's conservative Stage I tune.
You can look at the numbers there in STD and SAE and come to your own conclusion.
Can BenzBoost recommend Velos? Well, personally, their communication with us dropped off for whatever reason. A member on BimmerBoost reported a similar communication and support drop off after the sale and issues with his tune.
With the supporting vendors we have offering M177 tunes for the W205 C63 platform, it is hard to not say there are better options available.