There may be a distinct advantage to receiving stock options.
Restricted Stock Shares (and Units) generally cost an individual nothing at the time of award. At the time of vest there is a mandatory income event (without getting into possible 83(b) Election or Deferred compensation scenarios). The income event wil result in taxes being owed at vesting. If the company is still private this will likely be no market to sell the shares and you may be paying out of your own pocket.
Stock Options do have a cost to exercise, but the exercise date is chosen by the participant, not a pre-determined schedule. This gives greater flexibility for financial planning. Also you will generally receive more stock options than you would get for an equal value of restricted stock. This ratio is usually somewhere between 2:1 and 5:1. These added shares create a huge difference in leverage as the stock price grows. At some point in the stock growth, depending on the initial ratio, stock option values quickly outpace restricted stock values.
There are also distinct upsides to restricted stock shares. 1) you actually own a piece of the company. This means that your shares have value as long as the company does (stock options lose their value if the stock price is less than your grant price. 2) Being an owner means you have the rights of an owner, including being invited to annual shareholder meetings. 3) You can file and 83(b) election within 30 days of the award. This may result in a dramatic decrease in compensation that is subject to ordinary income taxes (talk to your accountant or financial adviser first)
The decision is never absolutely perfect, nor is it easy.
Hope this helped. ~Dan