Just wanted to let anyone who might be interested know that I ended up going for the Samsung PN51F5300 over the Panasonic 50" S60. They both looked roughly equivalent in the store and figured I'd start out with the one that was 1" bigger and $50 cheaper and if I had problems then return it and get the S60. It doesn't look like there is much of any anti-glare filter on the F5300, but the S60 doesn't have one either.
I have to say, when the room is dark the picture is amazing! We watched Star Trek (2009) on Bluray the night we got it and were blown away! It was like we were at the theater it was so big in comparison to our old 42"!
However, the reflections are pretty noticeable during the day since we have it in our living room and only have thin curtains over our big front window. I'm trying to determine if they bother me or not, however getting the S60 wouldn't help much since it also doesn't have an anti-glare filter unless it ended up being much brighter than the F5300. And even then it is really only the dark areas/scenes that are affected by the reflections so being brighter I don't think would really help anyways.
If I thought I could get a LCD/LED with a fast response time (to avoid ghosting and motion blur) and good quality picture for the same $650 range I might consider going that route instead since this is our main TV and will not only be watching at night, but it appears that to get a good quality LCD/LED you really have to go up and above $1,000. There was still a good amount of reflections on our old 42" plasma despite having an anti-glare filter (glass is glass after all) so the difference here mainly appears to be the reflections are roughly the same just less diffused.
I've got 15 days to return it so I'll keep evaluating it during that time.