To be fair to whoever you took the car to MAF problems can manifest themselves in SO many different ways it's not even funny.

I have had lots of instances of faulty MAF that haven't flagged fault codes in the ECU, I personally keep a couple in my tool box to swap out though.

You could try un plugging the MAF and seeing how it runs, normally reverts to a basic map and will run good enough to rule out the MAF as the problem. Other than that I had a Cayman S with a faulty fuel pump and was causing a slight misfire but that was in mid/upper range with heavy throttle.