I have always struggled with the tax consequences combined with the high volatility and lack of liquidity in receiving equity in a start up type of company, with the confusion of the tax laws around it. I don't mind paying more in taxes if I can delay the issuance of stock (in the RSU scenario), but I have a hard time paying taxes up front on something as volatile and illiquid as stock in a start up company. Hopefully the RSU scenario will get tested and more accountants / lawyers will be more comfortable with this scenario.