Souvlaki truck burns their meats upon occasion and so they can have a bitter taste from the high flames on the grill. Without the french fries their sandwich is kind of small. Their meat is never moist.
Gyro Gyro is a bigger sandwich, moist, and better prepared. Also, they seem to be the only place that knows how to fold and serve a gyro properly so you can eat it without a mess. They fold it onto a cone, and wrap it in paper cone, then place in a foil bag to keep warm.