Yeah a 3 year old thread!
Pros are simply better built, and will likely last longer. This is important especially for craigslist purchase, and for die-hard plasma fans who want their set to last as long as possible
They also have RGB high/low adjustments directly in the user menu, so calibrating the grayscale is easier, if one wants to keep the set calibrated throughout its useful life.
I own 4 of these sets and they look stunning after calibration, even the one with 20k hours on it. Did I mention they are built like a tank?
TH-60PF30U (2012), knowing what I know now I would've gotten 2.
TH-50PHD8UK (2014), my backup, for the kids/in-law, 20k hours.
TH-50PHD8UK (2016), backup of the backup.
When my kids watch cartoon on the TH-50PHD8UK, sometimes I watch it with them, just to admire how nice the image quality is.