I think Anarkitty and The Other Bandit summed up my point. People don't get these things because they are cool, they are mostly replacements for injuries. Dermal Plating, Bone Lacing, Wired Reflexes 1, Spurs, all of these I can see gangers and the like getting to help them survive. But what about the really expensive implants? Suprathyroid, fully Customized and Enhanced limbs, Adrenal pumps 2, Synaptic Boosters, etc? Where do people get the money for something like that? SR is a dystopia, with most people struggling just to survive, where are gangers getting 140,000Y for Wired Reflexes 2? Or 95,000 for an arm? 10,000 or 20,000 I can see for an upgrade to help you survive in the Barens. No, customized and enhanced cuberamrs are not going to be very common, even in the 6th world. Replacement prosthetics would of course reflect the social station of the user, obvious for a ganger and synthetic for a sarariman: they both want to fit in with their 'tribe'.
Shadowrunners are of course an exception. They can make a ton of money, but often get stuck in the cycle of continually upgrading for the next high paying job, only to use that pay out to upgrade again and again, hoping for that one last big retirement level pay out. While the typical sarariman won't care about lower capacity in his arm, he will likely be willing to pay a bit more for a synthetic one. So will a shadowrun team's face, as there is still enough room in there for some increased AGL, a smuggling compartment or a cybergun. The Orc sammie who took an auto cannon shot to save the rest of the team and lost a leg, he's not going to care about looking normal and is going to want that cybergun grenade launcher.