I always got great service from US Chrome. At least 1/2 th etiem, I had my cylinders back before their promise date. When I was riding my dirt bike, every weekend, I had actually memorized their address because of how many different cylinders I sent to them. The finish was always an upgrade, too.
When you have cylinders coated, keep in mind this finish is not a "chrome" finish like you would use on a car bumper. Its not unusual to see tiny imperfections, or odd colors, in the finish. I hate to even use the work, "imperfection" , its really not that, its just that its often times not a pretty finish.
Yours will probably look perfect, but dont freak out if its not.