...this is more the norm than the exception with even the larger/reputable manufacturers IME. You could have had the same experience with a Sony or Samsung, since many of these HDTV panels share parts. YMMV.
That said, the GT10 has great PQ. Worth the hassle since LED/LCD still does not compare.
I bought my plasma TV TC-P55GT30 in Nov, 2011 and did not purchase extended warranty due to my belief in quality of Panasonic TVs. In Aug 2014 I heard a cracking noise in the TV and it stopped working. Called Panasonic customer care placed a request for repair. The authorized technician checked the TV and said that one of the circuit boards need to be replaced which will cost around $400 including parts and labor. Panasonic agreed to pay $100 towards the repair due to the reason; it was less than 3 years since I bought the TV. I placed my complaint on 27th Aug 2014 and the part is expected to me delivered to the technician on 3rd Nov 2014. I am sitting without TV for more than 2 months. By the say I also own a Panasonic blue ray player and home theater. With all that said, I will not be purchasing any more Panasonic products again.