Plus the sony's look 10X better in my opinion. Not the screen but the plastic casings. All the others are so "fancy" my G500 is just square and simple.
Also, the Sony cases are easy access. 4 screws and its off. Try that with another company, no they have tabs that break if you open them, and it voids your warranty. They take a special tool when removing them so they don't break.
Also, to extend the life of your monitor, open the casing and blow it out once every 6 months. This keeps dust from shorting it out inside.
The G400/500 does have BNC inputs, in addition to standard HD15. This means you can hook two computers to the one monitor. Or use BNC for better image quality.
Also the E400 can only do 1600X1200@60Hz while the G400 can do 1880X?@75Hz