CNET did not review the Samsung LNC670 series of LCD TVs, which includes the 40-inch LN40C650 and the 46-inch LN46C650, but we did review the LNC630 series, which is similar.
The major feature-related differences between the two series are the inclusion of Samsung's Apps platform and a glossy screen on the C670, which also has a red-tinted frame. The contrast ratio specification of the LNC670 is also slightly higher, but we don't expect that to have a major impact on picture quality.
Aside from these differences, we expect the full review of the Samsung LNC630 series to provide a good indication of how the LNC650 models will perform. For additional information on Samsung Apps and the impact of the glossy screen, see the Samsung UNC6500 review.
The LNC670 series is exclusive to Best Buy, and as far as we know is essentially identical to the LNC650 series.