I played about ten games on the Metallica pin at expo. It's so modified that it doesn't really feel/play like an Earthshaker, save for the familiar Lawlor right ramp shot and setup. The art on it was phenomenal. The sound is good, but I would have done a few things differently. Like I would have put short guitar riffs in the pop bumpers instead of motorcycle rev'ing sounds. Or even drums would have been cool.
Still, all in all it was very very cool. I played it around 2PM Friday and I don't think it had a second of downtime during the whole PPE. By Sunday it was showing some wear and playing quite different, I noticed.