From what I understand and have heard from companies/people in the know is that a lot of companies claim they can "dyno tune" but it's a can-tune stolen from a company that actually has the software to adjust maps. They act like they're adjusting maps but they aren't actually doing anything other than upload a stolen tune. I know for a fact that Eurocharged has the Dimsport software, the only software on the market that can find maps for you, allow adjustment AND re-load via OBD for Mercedes. You can adjust in Win OLS but you have to find the maps or pay for someone to tell you where they are, then use the Dimsport MyGenius loader to upload it. Both you still have to pull the current file manually for, or have it on hand. I'm sure some go through the trouble but again, it's rare when both pieces of software are so expensive, even for businesses you think would have the money to afford them.

Basically all I'm saying is, be careful who you go to. If it's not Dimsport then it better be Win OLS with a Dimsport MyGenius loader, and they better have good soldering ability to pull the current file or have it on hand.

My .02, hope it helps.