It's pretty decent but I had to connect it with it's component out. When using HDMI and on some channels (that had almost 100% reception) sound was cutting every second or so and since my A/V receiver takes 2-3 seconds to detect the sound source (AC-3, DTS, etc) it was plain unwatchable.
My wife watch only live tv when she's not, well, *watching* the tv. Cooking supper while listening to the news for example.
Since then I upgraded my tv to a new flat screen with a built-in ATSC tuner and moved the old tv in the basement were no one watches live tv. (We use MythTV, an opensource PVR)
Bottom line, channel master suck with their tuners.