Kind of disappointing after reading numerous positive reviews elsewhere. I think you forgot to include "high price" in the negative column since you emphasized it in closing.
Ashamed Samsung is force feeding Tizen and reinventing the wheel with a choice consumers are not familiar with when we've successfully used superior Browsers in the marketplace for decades. Android, Chrome, Safari, Opera, and out of nowhere we get yet another crap interface to learn? Guess Samsung wants ownership/control of everything.
I suspect the Flat Panel Shootout later this week at CE NYC will further critique this considering a number of Calibrators and AV experts have been die hard plasma fans, one even owning four Kuro's that take great pleasure in trashing LCD's despite plasma numerous fail points in a bright sunny room and other shortcomings.
I strongly considered the 78JS9500 but could not bring myself to spend $10K and so I bought a 75HU8550 flat and a SEK-3550 OCB & UHD Drive for less than half. The SEK-3500 is getting rave reviews by most on AVSForum though it's having a few hiccups out of the gate most favor it as well worth the price. Thus, jumping at a clearance priced 2014 and a OCB gives me and others the best of both worlds at a consumer friendly price. May perform a shade shy of the JS but I have to live with the budget and compromise as Samsung just overpriced them significantly. Market share arrogance can cause that I guess.
Your review made me happier about the flat 75" HU8550 for my HT.