-Potential Burn-In: Because of the phosphor technology in Plasma TVs (see How Plasma TVs Work), it is possible for traces of an image to be 'burned-in' to the display. This is generally only a concern in commercial uses, where images are displayed for long-periods of time. Those that watch stations that offer news tickers may also need to be careful. Burn-in can generally be avoided by making sure that you do not keep a constant image on the screen for extended periods (sometimes as little as 20 minutes), either by turning the television off, or changing the channel.
-Lower Brightness: Although still considerably brighter than rear-projection TVs, direct v-iew and LCD TVs often are able to provide a brighter picture. This is generally only readily noticeable if watching in a very brightly lit room. Latest generation Plasma TVs have improved on the brightness issue considerably, and our only real warning would be to those that plan to do the majority of their viewing in a room exposed to afternoon sun.
-Not the Lightest or Slimmest: Although Plasma TVs are MUCH lighter and thinner compared to direct view and rear projection TVs, a lighter, slimmer technology does exist: LCD TVs. LCD TVs use the same technology as used in most laptop computers. However, it should be noted that LCD TVs are not generally available in the same sizes as Plasma TVs, and in those rare cases that they are, they generally cost considerably more.
-Shorter Life: Compared to other television technologies, Plasma TVs do generally have a shorter life span, and there is no option to repair a burnt out tube or backlight. Most Plasma TVs have a life span of 20,000-30,000 hours based on manufacturer's estimates. This life span is commonly referred to as the Plasma TV half-life, as it is the number of hours over which the Plasma TV will loose approximately half of it's brightness.
Of course, we should note that a Plasma TV with a 20,000 hour life would allow you to watch 4 hours of TV per day for approximately 13.7 years. Even at 8 hours per day, your Plasma TV should provide you with nearly 7 years of enjoyment. So, for most of us, this should not be an issue, and a Plasma TV is a worthy investment.
-Fragility: Plasma TVs are a very fragile technology, and the units are quite easy to damage. Extreme care must be used when moving them, as even laying the Plasma display on it's side can have adverse effects, possibly damaging the unit irreparably.