To me - Megadeth destroys Metallica. I used to love metallica and still do - but since listening to all the others - you realize how overrated they are.
There is no single Metallica song that holds a candle to this entire album. And I love Metallica too! Maybe Orion which is a masterpiece. But of the Big 4 Metallica is the bottom for me - Its Megadeth / Slayer 1/2 - Anthrax 3 and Metallica 4.
This to me is a FNG masterpiece.
Orion is one of my favorite Metallica songs. Fight Fire with Fire is up there too.
The Rust in Peace album is top 5 best in history, no questions asked.
I grew up playing the guitar, my cousin used to play covers for Guns n Roses all over the country. He's an amazing guitarist, still has a band today. When i asked him why he didn't cover any Megadeth songs, he just said they were too technical and needed 100% attention to not mess up on stage or get out of sync, very fast songs. Metallica is like that too, Het and his "downstrokes" only play style is VERY difficult. You have to be super fast.
I remember trying to learn Hanger 18 in high school. LOL Not a chance. It's top level skill. Try 194 BPM!

The best i could manage was Tornado of Souls, just the intro.

If you have never played guitar, you probably don't understand how amazing Megadeth really is, just from the difficulty factor.
They were very good in concert too, as long as Dave wasn't too messed up.