Took 5-6 weeks to get a frame from Austria with the "new" serial number (they prefix the upgraded frames with a 1 - ESTxxx becomes 1ESTxxx.). I paid shipping down, they had it back within a week over a weekend, including the night sights I had installed while it was down there.
Mine is a G-17 9mm, broke after about 7500 rounds. Customer service was prompt and friendly to deal with too.
The breakage was one of the little steel frame-rails. Apparently some were bent with a true 90-degree bend in them and broke at the bend after enough time and rounds. The new frame, and my G-26, both show a more arched bend to the rails.