The Sony XBR4 series of LCD TVs is very well-regarded among reviewers and consumers alike. I've had the opportunity to closely examine the 46-inch member of this line, and I found it to be a stellar performer in most respects, as did Tom Norton in his review. The KDL-52XBR4 is no different, bringing excellent picture quality to a 52-inch, 1920x1080 screen.

Many people ask me about the difference between the XBR4 and XBR5 lines. They are basically identical, with just four minor variations. The XBR5 has a fixed gloss-black bezel, while the XBR4's silver-gray bezel can be replaced with other colors if you purchase an optional kit. The XBR5 also comes with an RS-232 remote-control jack, a longer warranty (18 vs. 12 months), and a $300 premium over the same-size XBR4.

Like many upscale LCD TVs these days, the KDL-52XBR4 doubles the rate at which complete frames are flashed on the screen, from 60 to 120 per second. This is supposed to reduce motion blur, a problem endemic to LCD TVs. If it receives a 60Hz signal (such as 480i/p, 1080i, or 1080p/60), it inserts an extra frame between the actual frames in the signal; if it receives a 24Hz signal (that is, 1080p/24), it inserts four new frames between the actual frames to reach 120Hz.

A Sony feature called Motionflow interpolates between actual frames to create these extra frames, calculating where objects in motion should be in each new frame. This is intended to reduce judder from film-based sources, smoothing out onscreen motion. If Motionflow is turned off, the set simply repeats each frame two or five times, depending on the rate of the source signal.

Another interesting feature is the DMex (Digital Media Extender) expansion port on the back panel, which lets you plug in proprietary DMex modules that add new functionality to the set. The only one available today is Bravia Internet Video Link ($300), which connects to your home-network router and streams online content directly to the TV from partner providers such as CBS, AOL, Yahoo, and Sports Illustrated among others. At present, all of this content is standard-def.

The KDL-52XBR4 offers a number of video-processing "enhancements," such as Digital Reality Creation (DRC), Live Color Creation, and Advanced Contrast Enhancer. However, I normally find that these degrade the picture rather than improve it, so I leave them turned off.

Also of dubious value, at least with movies and TV shows, is x.v.Color, Sony's name for the xvYCC expanded color space facilitated by HDMI 1.3. Because no movies or TV shows are produced using the expanded color space, it's better to display them using the standard space on the TV. The only exception is when viewing home video that was shot on one of Sony's high-def camcorders that implement x.v.Color.