Sounds like a solid arrangement to me. I don't really like those injections of background guitar though in the chorus, I think they sound a bit like you might be trying too hard to put something in there. Some of the parts have a really cool descending feel that I think sounds almost classical which I like a lot. I think you could add something else to the final chorus though, maybe after the first run raise the harmony up an octave to add a bit of a developed sense instead of blindly repeating what happened before in the song. I like the old school sounding bridge section, although I think that you could shorten the soloed guitar to one measure, so when the other guitars come in it still sounds new to the listener. Also, maybe you could add in a guitar solo over the second half of that bridge section. I'd use a pentatonic to really keep to that old school metal vibe you have going on with it, just something fast and mean sounding.
Also this is more a mix thing, but during that part where the guitar is on it's own, I hear a bit of string noise so you might want to edit that out ;-) Everything else is just really tight so you don't want something like that taking away from it.
Sorry for massive post! I study music at higher level, classical composers and all that stuff, not music tech or anything so I like these sorts of things.
