I've gotten restricted stock units (orders of magnitude less obviously), and I definitely don't recall them working like a loan etc.

The transaction is that you get N shares over a K-year vesting schedule (cliff + monthly/quarterly vesting etc). The dollar value on shares that TC published is arrived at by multiplying N by today's GOOG stock price.

This is better for the employee than cash because the stock price in one year may be higher than today. For the same reason, it's better for the company to give shares instead of cash, since they can pay out less in today's dollars.