As a Metallica-fan myself I had to reply ofcourse! I really enjoyed your cover!
I also use guitarbackingtrack.com a lot. It has some great free backing tracks, otherwise I'm usually using Youtube.
Enter Sandman was one of the first song I learned on guitar but I didn't actually learn to solo so my feedback maybe a little dull lol. I thought your tone and sound were fantastic! The intro guitar sounded great and the rhythm guitar also had a solid tone. The solo however, matched Kirk Hammett's sound perfectly in my opinion! What a great sound.
I personally enjoyed your version of the solo, so keep up the good work.
I'm not that good at giving useful feedback but just wanted to let you know.
JJ