While we're talking about PTO, my last two employers handled it in very different ways.
Employer A gave me three types of PTO: vacation (4 weeks), sick and excused (2 weeks), and floating holidays (11 days). There were different rules associated with each type of PTO. Sick and excused was generally for illness or doctor's visits and had to get approval, holidays could only be taken in 8 hour blocks, vacation rolled over but the other two didn't, etc.
Employer B just gives me one bucket of PTO. Vacation, sick time, Christmas, whatever - it's all the same, and it's all eligible to roll over.
At first I was stuck in the old mentality and didn't like using PTO for sick time, but it's really much, MUCH better. I rarely take more than a couple sick days a year, so being able to use that time for vacation or roll it over is way better than just losing it at the end of the year.