I've owned a few 2407 Dell with the S-IPS panel as well as trying to find the "right" display at the $400-$600 range all from samsung to LG.. I've used Spyder 2 Pro to calibrate all the monitors and to this day all those monitors does not come close to the vividness/accuracy/depth of color/viewing angle/naturalness of the Apple Cinema Displays even right out of the box
That's because the Dell 2407WFP does not, and has never had, an S-IPS LCD panel.

They use an S-PVA panel made by Samsung.
All 30" Dells have S-IPS, while Dell 20" displays use a mix of S-IPS and S-PVA panels. I'm NOT talking about the "E" series models. I'm talking about the better Ultrasharp models that don't have an "E" in the model, such as the UltraSharp 2007WFP 20 inch model. The chances of getting a Dell 20" S-IPS display is fairly good if you buy a 2007WFP. I own an S-IPS version. I'm not sure about the new Dell 20-inch 2009WFP model, though. Check Hardforums.
My mom does graphic design and print work and we just switched her over from an ancient crt (she's in her early 60's takes a while to switch her to new things) to that exact same dell and she LOVES it. It's not quite as good as the ultrasharps, but it's close. The color accuracy is actually pretty good. She used the money she saved and got a Spyder ultimate calibrator to help with the color stuff and it's really beautiful.
I definitely suggest going for that one. Definitely the best for your buck.
Edit: the panel is a TN so it won't be as good as any of the sips monitors, but for a TN panel it's really nice.
There's no such thing as a "good" TN panel. Sorry. I think your mum may have lower standards, or doesn't really know what truly accurate colour looks like. Maybe she's happy because the colour accuracy is "good enough" for her prints, but it's definitely not accurate. Calibrating it is OK, but she's going to have to calibrate
very frequently to get anything accurate. I know you may want to believe that it's a matter of opinion, but unfortunately, in terms of LCDs, it's not really debatable. It's a technological issue, you see, and not something you can sneak past. It's like saying my car isn't as fast as an Aston Martin or Koenigsegg. It's not something that my car can offer technologically to get the same performance.