My only real experience with cyberpunk RPGs is Shadowrun (1st-3rd), I always found the essence stat a great indicator for the cost of using Cyberware. While the average joe didn't get any side effects until you hit a negative number (cyberzombies), it did confer a feeling of fleeting humanity. But to be honest, I got most of my RPing ques from the descriptions in the catalogs and the runner commentary, particularly memorable is the move-by-wire system that had you in a constant state of seizure (but the chip allowed you to move very quick and smooth). While the stats of that particular cybersystem where not bad, what really made it cool was the fluff text.
To be honest, i remember that in some of the later source books there were rules introduced for social penalties for certain kinds of cyberware, but those (like so many SR expansions) made the game unnecessarily complex.
I do agree that the cyberpcychosis needs to be incorporated in a cyberpunk RPG, but to what extend depends entirely upon the type of game you want it to be. I can see people wanting to treat it as some kind of insanity score reminiscent of a Call of Cthulu game, but personally i find that going a bit overboard. It really depends on how important cyberware is in your game, how strong it is, and how the rest of the game mechanics work. If it is like magic items in a DnD game, we relegate the amount of money the characters can have access to, so we can treat them like magic items and institute a limit on how many can simultaneously be equipped. This can be done on a location basis (arms, head, torso, etc.) or a cumulative count (like Shadowrun. Individual systems could have their own effects, an obvious cyberarm might give you trouble in certain situations, but would give an intimidate bonus as well. Bone replacement on the other hand isn't visible, but tends to set of the metal detectors at every school...
You might want to institute certain mental flaws at certain levels of cybernization, but these could be things a player chooses for his character (and gaining a bonus in some other way), could be forced at a certain level, etc. But players most player want the option to be able to negate such flaws, either by being part of some (prestige) class or through sacrificing a feat.
In short, it completely depends on where you want to go with the RPG and is it needed as a balancing mechanic. I don't doubt that people react differently to having cyberware implanted, it all depends on the person and the situation. Is it their choice, are they forced to do it (either by peer pressure, economics, or necessity), what are their phobias, etc. Some people adjust after loosing a limb, other become extremely angry at the world.
Last week they removed my Galle bladder, a relatively minor operation (i spent less then 48 hours in the hospital), but it freaked me out quite a bit. I particularly hate needles, so having one in my arm for an extended period of time wasn't a pleasant experience. Now i have three small scars on my belly and those freak me out as well. I can only imagine what would happen to my sanity if i had wires running out of my head and my arm was detachable... *brrr*