I would like to know how often in the real world a surge or some other anomaly comes along and puts a technician at risk while in the process of troubleshooting a fault in a piece of (let's just say consumer) equipment.
Since I discovered this site which has always stressed getting meters that meet their CAT ratings, I have wondered the same thing myself, only from a slightly different perspective, I always felt that if these surges were so common place, then there'd be be tons of folks crying about their busted electronics, like their 'spensive, flat screen, UHTV's, computers, smart phones (while charging), etc. I am sure they are not "hardened" for what would be considered CAT 2 transients, like a Fluke or other reputable multimeter, so there should be many failures of these kinds of equipment. And, if it were really a problem, there'd be an outcry to harden electronics to survive these transients. At least in the US, you don't really see that, which leads me to believe overall the US has fairly clean electric supply (as opposed to generation, but that would be a different discussion
), but as others have said, that may not be the case in other parts of the world, so a meter that meets its CAT rating may be more of a necessity in those areas. I have not known anyone who has lost a piece of electronic equipment due to a transient unless lightning was involved.
But, that said, I do understand the position of this site, its hard to argue being less safe and recommending meters that will obviously not meet their CAT ratings and could potentially put someone's life in danger if, for example, an Electrician is lead to believe that an UT-66E is just as good as a Fluke IV for much less, and the Electrician proceeds to buy and use his UT-66E on industrial equipment. I think that is why people stress that the UT-66E (and other inexpensive multimeters) is perfectly fine if your plan is to use it on what most folks refer to as "LV" circuits (i.e. <120V) and don't recommend using it to measure inside your electrical panel.