Originally Posted by lujan
I have both the 73833 and the 65738 and the 65738 is brighter but that may be only because the lamp on the 73833 is almost 4 years old and I'm still on the original lamp.
The other difference would be the smaller screen size. I would expect the smaller TV to be brighter even if both TV's have fresh lamps. But there's a lot more to picture quality than brightness.
I recently upgraded from a WD-65835 (a Diamond series model) to a WD-82838. In addition to the picture (obviously) being much larger, I feel the image quality is a reasonably big step up overall. I would also expect the image on the 738 series to be better than the 833 series given that the 738 is so many generations newer than the 833.
kjahadi - if you really need the 4th HDMI input, the wired IR input, or one or more of the other features on the Diamond series, then you should definitely try to get them to replace Diamond with Diamond (or offer to pay a percentage of the difference in price to go from the 738 to the 838). Otherwise, you should probably be happy to settle for a brand new 738. Either way, you're probably getting a pretty good deal.