Is this basically the same monitor, but the LED will be more energy efficient? They're basically the same price. The LCD seems to be more popular (more reviews), but that's probably because it's been out longer. Any opinions?
Al consumer level LCD monitors with LED backlight are edge lit instead of having a full array backlight. Full backlight array means the light bulbs (CCFL) spans the entire back of the LCD panel. LED backlight originates from the edge of the screen. This means LED backlight can be less uniform than full array backlight, but even full array suffers from uniformity issues. That means certain parts of the screen can look darker than others.
LED backlight allows for lighter and thinner monitors. It also uses less electricity.
Some LCD monitors with LED backlight may have slightly bluish colors because blue LEDs with a yellowish phosphorous coating is used to imitate white.
LEDs are cheaper to make, and a very high end CCFL will tend to outperform an LED to a videophile, IIRC. This generally doesn't hold true as a rule, as costs are cut on most all products nowadays but some more expensive monitors may use CCFL backlighting to a better end.
CCFLs are also less enviromentally freindly, so if you love the trees, go LED.