Bear in mind that most pro labs use dip and dunk machines which never let the film come in contact with any service. Local labs have machines with rollers which transport the film and have constant contact with the emulsion. Personally, I use local labs like Ritz camera to process my 35mm film and I really haven't seen any serious scratching. If you scan your film you may want to consider the pro labs since scratches are more apparent on film during scanning.