The comparison is not between LED or LCD because both type of monitors are LCD.
The question is CCFL or LED backlights. LED is low power, thinner and doesn't need a warm up time, thats it.
LED backlit panels have been on the market so quite some time now. Almost all laptop screens are LED because they need to be thin and low power but nobody advertised it in the past because there is literally no advantage.
Now with marketing and advertisements they managed to convince people it is an upgrade so they can attach a price premium to it. Similar to apple products. It is ALL MARKETING.
I would go for LED because graphics is much clearer with LED. The difference of both is LCD uses backlight in the middle of you monitor aligned in a row then emits light. While the LED uses tiny backlight at the edges of your screen aligned in row horizontally and vertically.
If you look more closely and compare an LCD to a LED the edges of LCD screen seems darker compared to the LED. LED distributes light all throughout the screen, that is why it is much clearer than LCD.
If you are thinking of buying LCD or LED, I would choose LED... seeing that it is brighter, clearer, and more new compared to the LCD. The downside is, the LED is much more pricey than the LCD.
If you are a gamer or a movie addict/fanatic and wants crisp and clear QUALITY graphics, I would choose LED with FULL HD capability.
The edges of CCFL backlit monitors appear darker because the rotation of the LCD crystals of crappy TN monitors have really bad viewing angle.
LED backlights are just more bright and colder, less power consuming. Probably too bright anyway. Though my CCFL backlit monitor have 470cd/m which is greater than my LED monitor at 350cd/m but my CCFL monitor does consume a whopping 140W so it gets really hot.