Definitely understand where you are coming from. If I wasn't already invested with my current sammy, I would likely go with a GT30 myself, but its so much easier to have 1 type of 3d glasses. As for the filter peeling, my D7000 fortunately has been clear of any peeling issues. And for the brightness pops, i've seen em from time to time, but fortunately, with Cinema Smooth turned on, they NEVER happen, and I use CS 90% of the time.
And like I said, I have no doubt that the Panasonics do a good job with the 3:2 pulldown, but 3:2 will never beat 4:4.
When it comes to your concerns, dithering is unavoidable with plasma, it's just how they work, but unless you are gonna be chillin 2 feet from your set, you will never see it. As for IR, the Panasonics are supposed to be worse than the Sammys this year, but when it comes down to it, unless you abuse your set, at you make it past the first 100-1000 hours, you should be fine.
Passive 3d is great, but ill take active 3d at full resolution over passive at half any day.