They distinguished themselves with superior black levels, accurate colors, and better off-angle viewing than LCDs. They did have some downsides -- namely their relative heftiness compared to LCD, a perceived propensity for burn-in or image ghosting, and an inability to deliver 4K resolution without costing a fortune.
Today, some 8 years into its lifespan, my plasma still works fine. It's mounted inside a wall-unit and while it doesn't have the slick, translucent frame of some of today's TVs, it looks quite presentable with its simple black border. No longer the best 65-inch TV on the block, it's been surpassed by LG's OLED televisions. I have one of those in another room.
The LG is a 2015 model, the 65EF9500, that I bought as an open-box item for a little over $4,000. Around the holidays last year, there were better deals on the 2016 version, which hit a Black Friday low of $2,800. But so it goes; even we so-called experts screw up on the timing of our purchases.
That plasma still looks pretty good to me
The plasma is a 1080p resolution TV. The OLED is 4K resolution TV. Does the resolution bump on the OLED make a difference? Not really. In both rooms I sit about 10-12 feet away from the TV, and at that distance, it's hard to tell the difference between 1080p and 4K.
I have done my best to take advantage of the LG's 4K resolution. I have an XBox One S, PS4 Pro and Roku Premiere+ connected to the TV. I play HDR-enabled games. I stream the limited amount of 4K and HDR content from Amazon and Netflix. I occasionally watch a 4K Blu-ray.
The biggest difference between the OLED and the plasma is that the OLED is brighter and the colors pop more. Oh, and the 4K resolution does come in handy for 3D movies -- the LG, which uses passive 3D technology, is hands down the best 3D TV ever made. Not that anyone cares about that. Or at least LG thinks so, because its 2017 OLED TVs won't have 3D capabilities. Bummer. They're still be great TVs -- and certainly better than my Panasonic plasma.
But I still like the plasma's picture. Rarely, if ever, say to myself that I wish I was in the other room watching the OLED.
Perhaps part of the reason for that is that I have better sound in the room with the plasma. I have a wired 7.1 system that's powered by a real AV receiver. In the room where the OLED is I have a Sonos Playbar. It's pretty good but not as good as the hard-wired system with 7 separate speakers and a wired sub.
Sound does make more of a difference than you think when watching a TV. But ultimately, what it comes down to is that the differences between my old plasma and new OLED aren't that great, especially when watching TV programming -- you know, that stuff that comes out of your cable or satellite box.
Plasma vs. OLED: My family doesn't care
Someday, I'm going to replace the plasma. But I'm not in any hurry to do it and neither is the rest of my family; they don't seem to care about which TV they're watching. It's much more about what's on the TV that matters and whether enough PS4 game controllers are charged. That's what they fight over. Not whether they can watch the OLED instead of the plasma (sadly, they could care less about 3D).
I figure that plasma's got another 3-5 years. OLED will be quite mature by 2022 and who knows, maybe we'll have 8K TVs by the time I decide to put the Panasonic out to pasture.
Of course, you won't be able to tell the difference between a 4K and 8K TV, but you'll still need a reason to upgrade. Right?