HD picture quality?
YES, the scalers job is simply to make the incoming signal match what the display can understand (native resolution). But, that does not mean that all scalers are created equal, scaling does effect the image quality, but usually in a bad way. This is due to the simple fact the the scaler has to add false information to the image to make it larger. As in, we have to increase a 480p DVD picture to make it show up on a 1080p display, since 1080p has more pixels(or picture info), we have to fill in the missing picture info till it reaches 1080p and this can result in a soft or rough picture. The scaler is so important that some people only buy products based on what type of scaler the company uses inside their displays. And you can even purchase separate scalers to perform the task instead of your display doing all of the work.