I like both bands but I will say this...Winger is actually much more talented.  Metallica had a cooler image, and Winger def. got a bad rap (which they might have deserved with Kip's ballet moves and playgirl appearance) but Reb is a lot better than Kirk and Kip is a REALLY good musician.  If you listen to Winger's unreleased demo stuff or the album Pull, you'll see what I'm talking about.