If you want to make it scary and go beyond Personafix, try this -
Chipping a personality for undercover work was fine for the 50's. These days, though, it takes something more. Forget a few active skills at low levels, these days you need James Bond in a chip: skills, attributes and all. Works great for the mob, too. So the companies got together, pulled out the old Dreamchipper files and said "how do we take this to the next level"? What they came up with would chill a sane person's blood.
The new personafix has it all. Just slot it in and you become the person on the chip. Mental Attributes change, skills shift to match the chip with no maximum. Its a dream come true. . .almost. There are a few things about the new persona chips that the corps don't want to become public:
The new chips have nothing to do with personafix chips. Instead, they are a highly compressed artificial intelligence. Put the chip in a commlink and its nothing special. Slot it into someone's head or a a commlink running a BTL capable sim module and it unpacks itself. . .into the user's BRAIN. Certain key components stay on the chip but the user's spare brain processing capacity is used to do all of the heavy lifting. So far the initial tests show that the chips can simply be removed bu there just hasn't been time to study those pesky long term effects. What are the AI's goals? Can they eventually take over the users? Do they really have the parent company's interests at heart?