I consider the pads on sanders, regardless of brand, as "disposables" just as the abrasives are. They have a definite lifespan, that varies with how often they are used and how hard one might press on the unit while sanding. I replaced the pads on the PC sanders I used to use a number of times and have replaced the pad on my 150/3 once, too. Let's not confuse machine quality with the normal (and variable) replacement cycle for wear items on our tools, whether they are hand-held electrics or big stationary machines.
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The most expensive tool is the one you buy "cheaply" and often...