I'm a big advocate for doing a power audit of a single family residence starting at the meter (which the power company will pull so you can see if there is any corrosion at the contact points) and having the feed traced to the main service panel which can be inspected and checked for hot spots and arcing; how secondary service panels are wired; the condition of the receptacles as well as their polarity (which the cheap hand-helds can do) before spending money on black boxes. I prefer to use electricians who are qualified for commercial work -- I find they often have more experience with the sorts of demands that audiophiles impose (which may seem crazy to the uninitiated). Eric, you are right, not just in terms of basic safety, but many times, the issues that cause people to look for power solutions have their origin in old or questionable wiring. We've mostly owned very old houses, the previous one dated back to the 1780s with many additions and expansions over the course of a couple centuries. Many days were spent by the electrician tracing and removing/replacing old wiring.
My present house is circa 1880 but was completely restored to museum quality standards, starting with a new foundation, circa 2004. We nonetheless did a thorough audit, installed dedicated lines on kitchen appliances that were not called for at the time of the 2004 renovation and all of this had nothing to do with the hi-fi sub-system, but gave us peace of mind.