Nigel, the same holds true for most technical devices, vocal processors, mics, amps, etc... The big box stores tend to be staffed by high-school kids that have trouble walking and chewing gum at the same time. I've encountered this a lot at GC. Fortunately, when I go into GC I know what I want well in advance and know the product to some degree by doing some research on the forums and the manufacturer's web site.
Cheers,
Gary
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PSR-S950, TC Helicon Harmony-M, Digitech VR, Samson Q7, Sennheiser E855, Custom Console, and lots of other silly stuff!
K+E=W (Knowledge Plus Experience = Wisdom.)