TCL

Update April 26: TCL has announced pricing and other details for the 6 series. Read CNET's updated preview here for more information.

Original story published Jan. 8 at 1 p.m. PT follows:

Last year TCL's P series was the best 55-inch TV for the money and its successor, the 2018 6 series, looks even better.

It keeps everything that made the P series great -- namely full-array local dimming, compatibility with both HDR10 and Dolby Vision HDR formats, and Roku's excellent Smart TV system -- and adds some performance and styling improvements.

Now playing: Watch this: TCL 6 series looks like a video quality value winner

The biggest improvement, however, is the addition of the 65-inch size that went mysteriously absent last year. The 6 series will come in two sizes: 55- and 65-inch.

TCL

Local dimming, which illuminates different areas (zones) of the screen independently, is one of the best ways to improve LCD image quality. TCL has upped the number of local dimming zones to 96 on the 55-inch version of the 6-series and a whopping 120 zones on the 65-incher. Compare that to Vizio's M series, one of our favorite TVs of 2017, which only had 32 zones. More local dimming zones usually mean better image quality because they allow more precise control of screen lighting.

TCL also talks up a new iPQ engine, said to offer accurate color without requiring additional adjustments or calibration, and a new HDR gamma feature that allows you to adjust the image to handle both bright and dark rooms. The sets can also reproduce full DCI-P3 color, and utilize "NBP Photon technology for even more realistic colors," according to the press release.

TCL

TCL upped the styling ante in 2018 as well with a slicker finish and power button detail.

Like its predecessor the 6-series comes with a voice-capable remote, and later in 2018 Roku will debut its own digital assistant to take full advantage of voice commands.

TCL also announced the 5 series of Roku TVs, which lack local dimming but do offer most of the 6-series other picture quality extras. It comes in sizes from 43- to 65-inches and also ships in spring for as-yet-undisclosed prices.