What's the difference between these monitors?

Just the stand, really. But since you have been looking for a good monitor, I could only recommend the Dell P2417H. It has a height adjustable stand with pivot, tilt and swivel, plus a good driver to adjust the brightness from Windows, without opening the OSD. I know it's not curved or anything, but I would rather pay the extra £15 for the stand and the quality, and I don't mind the lack of the curve.