I grew up in the metal and punk hardcore scene I've listened to all the bands you've listened. The shit all starts sounding the same after a while, just like rap does. I wish metal would add more than just bass, drums, gutiar and vocals. I know WOP does this with keys, but other than that ain't much happening nowadays in my opinion and sounds like every metal band is copying Cattle Decap and The Acacia Strain..
This is kinda why I stray away from the newer metal acts. I mean there's exceptions like Mastodon, who've kinda made their own way, but really I think it was best back in the 80's, particularly Megadeth, Slayer, Anthrax, Testament, Suicidal, etc.