I usually only do a function check...
And a visual inspection of new, but then, I rarely buy new. ON a used gun, if the field strip is simple and quick, I will ask if they mind. If they do, then I ask them to do it.
On the last Auto Mag I bought, however, I did do more than a field strip, and I had the Auto Mag marked tools to do it with me.
The store clerk had no idea how to even do a field strip, and not only allowed me, but watched with interest. I was interested in checking the recoil rods, cocking piece, bolt rotation spring, can pin, accelerator, and a couple of other critical parts to ensure there no broken, or damaged/missing parts, so hopefully the gun has a chance of functioning.
Note that I had already commited to buying the gun, and was going to buy it no matter what. But that is nowhere near the same situation as buying a stock model duty autopistol "off the shelf".