Compared to the Dell Ultrasharp 2407WFP the ViewSonic marginally outperforms it in the image quality stakes but not by an awful lot. It’s marginally brighter, and ever so slightly more vibrant but the Dell does have a faster response time at 6ms grey-to-grey.
In which case there isn’t a great deal between the two, and making a choice is difficult. Though the ViewSonic has marginally better image quality, the Dell trumps it in most other departments providing more features and far superior adjustability. HDMI could be claimed to be advantage in the ViewSonic's favour, but since its presence is at the expense of a DVI port the difference is negligible – one could after all use a DVI-to-HDMI adapter to the same effect on the Dell, which is also HDCP compliant.
Ultimately, in an ideal world everyone would ignore both those and go for the BenQ FP241W, which is now available for £545. Obviously, if you don’t have that kind of money then you'll have to go with something else, in which case this or the Dell are probably your best options. Which you go for will depend on your needs, though in my mind the Dell is still a marginally better investment thanks to its superior adjustability.
ViewSonic has done some good things with this 24in display. Most importantly, image quality, though not flawless, is very good, with strong colour reproduction and a bright display. It's in design however, that it lets itself down, with a disappointing level of stand adjustability that pales in comparison to its competitors.