We have been using Happy Limo for the last few years and it has worked well, although it is pricey. We often take an early flight home (7:00 a.m.), so a 4:00/4:30 a.m. pickup is usually necessary. That has always been fine as well. We did not travel to WDW last year though.
We’ve used Tiffany Towncars as well with no issues.