I cannot comment about the quality of BMW's current wheel lock offering, or a particular dealer's aftermarket offering, but here is my story...
I have a set of "BMW" wheel locks that are now 14 years old and they work as well as they did new. Once a year I flood them with WD40 followed by a graphite and oil lock lubricant. I believe the reason they have done so well is that they have never seen an air hammer -- I always hand torque lug nuts. They seem to be of a high quality, hardened, blue steel material...rust free. I too wasn't impressed at first with the wheel locks because they seemed too "stubborn" with key alignment. I don't like to jiggle a key to make it fit. I was concerned about being stranded, unable to unlock in the rain, sleet, snow and mud. However, they have proved much more reliable than anticipated. I have never had any trouble removing these locks...with the key of course.
I am in the market for a new set for the M5 but haven't had a chance to investigate what the dealer or others offer today. If there is a superior set, I'd appreciate hearing a testimonial.