You don't want to look like your taking too much time off and be abusing the policy.
It is good although that sick days tend not to count for these limits.
It's also good for employees in that I don't have to haggle over PTO whenever I want to take a vacation.
Haggling with your employer over time off is terrible. It's a poor experience--I shouldn't lose 3 days off of Christmas vacation just because my butt wasn't in my chair an additional 8 hours during the previous 11.5 months.