Steve saved the day (or night)! My friends who were staying in my apartment broke my key in the lock at 10:30 pm on a Sunday night and were left standing in the cold.
They called me in a panic, and I called them, tech Steve showed up within 10 minutes and got them back safely into my apartment within 10 minutes flat.
Out of all the locksmiths I have used in London (and over the course of more than a decade, there have been many!), Steve has been the most responsive, the most reasonably priced, and also the most willing to educate and explain about the pros and cons on my current lock.