It's not LED.
But it's a desktop monitor. You're not moving from conference room to conference room and need the screen on and ready to go instantly like with a laptop.
It's going to take 3 seconds to warm up when you turn it on in the morning.
At 400nits its brighter than the 24" ACD anyway. Also you won't get better blacks from an ACD.
Did I mention it's matte!!!!
After 3-6 months use of the CCFL backlighting monitors it will take 2-3 minutes to get to full brightness. And after 1-5 years it'll take almost 5 minutes to warm up. I'd take the LED backlighting which produces much cleaner pictures and easier on the eyes with instant backlighting which hardly ever dims and looks as bright as the first day I turned it on even after 10+ years!
My 24" LED ACD is almost a year old (this december as I bought this display last december) and it looks as bright as the first day I turned it on with instantaneous clear vivid image when I turn it on in the morning (or occasionally off and on as many times I need to during the day).
I owned the 23" ACD, 20" ACD, 30" ACD, Dell 2407 and 2408 both S-IPS panels using CCFL backlighting, and after 6 months use I always have to crank up the notch of brightness by 2-3 notches more just to match the original 1 notch or even 0 notches of brightness when the monitor was new.
Thats the reason I love the LED display, it never dims after months/years and it turns on full brightness without looking blurry/muddy instantaneously.
I dont know why but I feel as if all monitors should be LED backlit by now (but I have no idea why only laptops are offered with LED backlighting but not the desktop monitors).
Like I always mention about my 24" LED ACD, out of all my toys thats on my sig, I love my 24" LED ACD the best!
The sad part is that most desktop monitors with CCFL backlighting looks less vivid as to say even my 17" mbp which does have the same 1920x1200 resolution but has a crappier TN panel. I guess TN vs. S-PVA on most average monitors. Anyways everyday whenever I turn on my 24" LED ACD my eyes goes @_@.
Especially when you run some high resolution games (I.E. the new Batman game I installed under bootcamp on my mac pro, my gawd!! Joker's face looks incredibly vivid, even better than my sony bravia xbr6 could ever reproduce!!). All I can say is that it looks INSANELY VIVID!!