These are two excellent stories and my kids love them as much as I do. Unfortunately, Warner Bros appears to have done the DVD on the cheap.
The overall color is much improved, very bright and vivid (the yellow Grinch not withstanding), but absolutely no effort was made to clean up the picture. Defects and noise that don't show up on VHS are very distracting on the DVD. There are several scenes where you can see the background disruption caused by layering animation of the Grinch over a static background. Probably normal back in 1966 for television animation, but a real indicator of the lack of effort put into this DVD. I also see no reason that the fade-to-black cuts designed for commercials could not be deleted, I could do that on my home software with almost no effort.
Since Warner Bros does not advertise this as remastered or enhanced then I guess there was no foul on their part, but I expect a quality improvement when an old classic goes to DVD. That is the reason most people buy DVD's to begin with. I don't know how a company can expect you to spend money to replace movies you already have on video if they don't give you something for your money.
The background pieces are good, but these are not new. All Warner Bros did was toss a couple of existing products on the disc. Once again, the least expensive route.
Warner Bros is also on a cost cutting binge with their DVD cases. This was the first of many Warner Bros DVD's I bought or received this Christmas that came in fiberboard cases rather than the standard plasctic DVD case. I suspect that these cheaper cases will not stand up to repeated use by my children.
I will definitely think twice before buying another Warner Bros product anytime soon.
Overall, I recommend both of these stories/cartoons to everyone, they are the product of genius, but until a remastered product is released I recommend the VHS version.