I don't have any personal experience with the set, just going by what I've read.
Pausing a show that has no hard logos, etc. probably wouldn't be as bad, but you still wouldn't want to do it for an extended amount of time. If the CNET accidental burn-in test is any indication, Samsung might have the edge in terms of IR resistance. It will vary from panel to panel of course, but some GT50 owners claim they have no IR issues, while others have gotten IR after only a couple hours, sometimes less. The set will always become more IR resistant as it ages, but it seems like IR is hit or miss on Panasonic displays. That's my interpretation at least, but in reality sets that are more prone to IR might only make up a slim margin. Personally, I decided to go with the GT50 anyway, I don't think you can beat Panasonic's overall picture quality.