I love Metallica. And when you feel that way about the music that they made, doesn't matter what kind of records they do. They quit metal a long time ago, so I don't expect to find another "Master of Puppets" on any new album they might do. They have done enough for the metal genre to now have permission to do what they want. It's like any artist who made a masterpiece, they can't make it again. Most of them just copy themselves for years to keep on making money and please people who just want to hear the same tune over and over again (like AD/DC did, and they admit to have done it). When I saw them playing in my country, in '99, they made so much noise that it appeared in all local newspaper. They still can rock. Anything else, is their personal choice. And of course, if you are a Metallica fan, you'll like anything they do.
About the media expossure, well, I don't think that's really important. I mean, should a band suck just because they are played on the radio? In my country the radio plays a lot of what in the rest of the world is known as "anti mainstream music" or "non comercial music". Bands like Hammerfall, Queens of the Stone Age, Fear Factory or Symphony X were "popular" here long before they start to appear on MTV. What MTV or the radios do with the music, that over expossure they made, is just stupid and has no significant meaning to what a music decides to create an put on an album. The musical industry and the musical sense of art are completly different things.
By the way, if you don't like what the radio plays, I must say that the song "Master of Puppets", "One" or "For whom the bell tolls" is played at least once a day in a local radio, unlike songs like "Enter Sandman" or anything post black album. So, the fact they're played on the radio means they are crap? Hey, arround here even Nightwish, Therion and Black Label Society are played on the radio.
Sorry if where you live, the radio is crap