ah i see. Well put it this way. The Acer 1916W and Viewsonic VA1912W are both very popular round here, and receive a lot of praise. They are both well priced and some people are very keen on the WS format instead of the traditional 4:3 19" models. They use a TN Film technology panel from a company called Chi Mei Optoelectronics (CMO), not one of the key players in panel manufacturing, but they've still done a good job here. They've made a good panel and it has been widely incorporated in the 19"WS market in these models as well as a few others.
There aren't many panel manufacturers making panels of this size (ie 19"WS) and the only other one which is in the picture, is a panel made by Samsung (more of a key player). They have already had a lot of sucess with the 19" 4:3 panel, again based on TN Film technology, which was widely used in models about a year or so ago. Some of the most popular and well established 19" models of the last year have been built around this Samsung TN Film panel, and these inlcude the Samsung 913N and Hyundai L90D+. These are both very popular, and there's plenty of info on them in the sticky if you're interested. Samsung have basically used the same panel, but altered it to be in WS format, and so have taken the winning formula from the 4:3 models, and made it available to monitor manufacturers for their screens. They used it themselves in their own Samsung 940MW, but not many other manufacturers have used it yet. This is probably because it is either more expensive to source, or maybe not quite as widely available.
Most 19"WS models so far tend to be using the CMO panel as i've said above, but the Hanns-G HW191D looks like (from the spec listed) it might be using Samsung's panel instead. This should be good based on the fact that their 4:3 version was very good
hope that helps a bit