BenQ is a staunch supporter of AOU's VA panel technology (logical as BenQ owns shares in the panel manufacturer), and that hasn't changed with the EW2430. Generally, VA is inferior to IPS (as found in the likes of the Dell UltraSharp U2410, most notably in the viewing angles department. But it does offer the potential for faster response times and is vastly superior by default to TN. As to the BenQ EW2430 specifically, the positives outweigh the negatives by a significant margin.
As usual, BenQ's contrast claims are a little overstated, to say the least. 3,000 native and 20 million (yes, actually 20,000,000) dynamic is the stuff that even plasma televisions can only dream of, and largely meaningless. However, contrast really is very good, and colours are vibrant without compromising on accuracy.
The otherwise even backlighting is too strong, even at its lowest levels, for blacks to be perfectly black, but you'll only notice if you're staring at a completely dark screen or when paying close attention to the black bars in movies. Tellingly, the EW2430 not only manages to distinguish every dark shade in our greyscale test, but did so without losing detail in whites. This is something that even the best TN-based monitors struggle with, and means you'll see every last detail in movies, games and photos.
Things are helped along by the lack of backlight bleed and some decent, if not exactly flawless, viewing angles. Both vertical and horizontal viewing is inevitably weaker than IPS, but stronger than almost every TN we've come across (with the exception of the amazing panel found in the Samsung Series 9 900X3A), and certainly adequate for daily use.
Vertically, colour shift becomes visible only from the top, which is the least likely viewing position. Horizontally we do see some loss of contrast and colour fidelity at around 165 degrees, but this is already more than you would usually be sitting at. Basically, you can happily view this screen with a group of friends or family without any issues. One minor point worth noting for imaging professionals is that there is incredibly subtle contrast shift even when sitting fairly centrally, though it's so slight it's barely noticeable.