So which one is better?
Both of the major types of projectors have their advantages. Because DLP often has a white filter, in poor implementations its colours can look washed out when compared with an LCD. In addition, LCD screens make more efficient use of power, operating at a higher brightness to wattage ratio. It is also important to know that if you are displaying detailed images such as spreadsheets you should strongly consider an LCD projector, as they project a sharper image than DLP. The DLP will still be readable, but there is a noticeable difference when they are placed next to each other.
LCD projectors can suffer from flyscreen and banding issues, which can be troublesome for long periods of viewing. The flyscreen effect refers to the black lines between each projected pixel in the image. It is more common on LCD than DLP projectors as the pixels are further apart with LCD. However, this issue only seems to occur in lower-priced LCD projectors. The higher-end models generally don't tend to have any flyscreen problems at all.
LCD can also suffer from banding where the coloured pixels from the different LCD panels don't land quite right. This results in a variation of tones on an image, particularly on large flat areas of light colour. Both of these issues are less likely to impact on the quality of basic text but are more prevalent with media and video. Nonetheless, if your presentations involve a lot of animations and video footage, a DLP projector may be more suited to your needs. Again, high-end models don't tend to fall victim to this phenomenon.
The newer technology offers much better contrast than its competitor and at higher resolutions almost completely eliminates pixilation of the images. As a result, many people consider DLP projectors more suited to the home theatre. However, if you find yourself regularly giving video presentations then this is definitely a big bonus. LCoS projectors offer even superior video performance, with higher resolution and a complete lack of visible pixels resulting in an incredibly smooth picture. Colour is also managed better than their DLP counterparts.