I got my 2407 last week, replaced a 2005FPW. Perfect, no dead pixels whatsoever.
However, I'm not so sold on the upgrade, it's a HUGE motha, unless you have good use to the extra screen space you'd just be wasting your money. I had no problem using the 20" to full, I have to work much harder to use the 24".
I use it mostly for writing software, so a larger screen is always better, but ironically, where I do need the extra space, the difference between the 24 and the 20 is not big enough. It's not like getting another screen, with which you could fit a PDF alongside your code, for example.
So I have a huge screen that I can't fill with standard everyday use, and for professional use it's not large enough over the 20" to really make a difference.
I also suspect the 2005FPW had a little bit nicer colors (and it never ever had ghosting, not in my eyes at least).
Movies are entirely different thing altogether; Although I don't use mine for movies, I'm sure the 24" will be a star on those, and furthermore, the 20" is 30 vertical pixels short of being a 1080p display.
Good for gaming too as games that only support 4:5 aspect ratio (like Battlefield) only get 1280x1024 on the 20", while you could get 1600x1200 on the 24".
But I only had it for a week; My experience leads me to believe that in a month I couldn't go back to a 20".
It's a mixed bag overall. Can't say I'm stoked with my 2407, but that's just because the 2005FPW has been such a revelation compared to my old CRT (not a bad one, Eizo T761). But I like it and I think I'll grow to love it in a month.
If you have the money, get it, if not, you might think twice. It's not a bad buy by any means though (and among 24" screens, I doubt you could find any better than the Dell).