I like the accrued "bank" that gets paid out. I had 83 days of "terminal leave" when I got out of the service. Instead of discharging you immediately and paying for those days, the service puts you on what is called terminal leave and you keep all your benefits of being in the service until you leave runs out. You mail in your ID and you are discharged and you don't have to return to the base/post to out-process.
I've never worked for a company with unlimited PTO, but it really is limited. You have to find time in the schedule to take your time off w/o out dumping your work on your team, so it's easier for them to deny 1-2 week breaks and prefer that you take more frequent, shorter absences.
The only company I recall since 2000 that used the "use-it-or-lose-it" policy gave 10 days sick/PTO on day 1 of your first year or some pro-rated portion thereof. Then, on Jan 1 after a full year of service, you'd get 1 extra day added until 10 yrs of service and then another week added on Jan 1 after 15 yrs of service and another week after 20 yrs.
Because it was both PTO and sick time, and flu season starts in the winter, you had to keep some time for Nov/Dec illness, but they wouldn't let everyone take the last week of Dec off at the same time, so some people got screwed when they used the last of their PTO in early Dec because the people with more seniority got to save theirs until the last week and they got sick w/ no PTO left. They'd come to work sick and spread it, and then half the office would have to take time off the first week of Jan due to illness.
They would frequently refuse to allow people to take/use their PTO before their 2 weeks notice, so I had to take my remaining PTO through Dec 31 and give my 2 weeks notice on Jan 2nd. Luckily for me, they waived the 2 weeks notice and paid me for the rest of that day while I transitioned my work to someone on the team, cleaned out my desk and did my exit interview, but they decided to not pay me for the 2 weeks notice I provided (which I expected based on their past history), so next job's start date was already scheduled for the following Mon meaning I only had 3 days of unpaid break between jobs and I got to use all of the PTO they had given me.
I'd heard from others who left voluntarily, or had been forced out (individual firing, not LR's), that even though we got our lump sum PTO on Jan 1, if they'd used more than the prorated portion they'd have earned by the time they were terminated, the company would garnish their last paycheck to claw back the PTO pay. I don't see how that's legal since it's a use or lose, not accrued PTO balance that you earn each paycheck.