Generally, people cannot tell the difference between 5ms and 2ms. "LED monitors" are simply LCD monitor with LED backlight instead of the traditional florescent (CCFL) backlight. LED consumes less electricity and since the are very small the LED lights are around the edges of the LCD monitor ( commonly referred to as edge lit) as opposed to "full array" for CCFL backlight which is directly behind the LCD panel. This means LED backlit LCD monitors are thinner lighter and consumes less electricity.
LED backlight is not truly white. Blue LEDs are used with a yellow phosphorus coating to imitate white. The vast majority of times this works well, other small percentage of times people may notice a colors have a slight bluish tint.
Many people seem to like glossy screen LCD monitors because it makes colors "pop". However, you need to deal with reflections.