Hey, Kev, that is some rippin guitar work. In fact, what I could hear of them, the bass guitar and drums were performed well, too. This song lends itself to a hard rock version, and your arrangement rocked. The one thing that drew my attention the most was the lead vocal. There are some pitch problems that need to be addressed. I don't know if your headphone experiments had anything to do with the vocal, but it sounds like the vocalist couldn't hear very well during tracking. It's not so far off that a pitch correction program couldn't fix this easily.
The other thing that drew my attention was the fact that the instruments sounded like they weren't in the same room and they seemed narrowly panned. As noted above, the bass gtr and drums were low in volume compared to the lead gtr. As for the f/x on the vocal, I think it might work if all the instruments are balanced and panned well. The good news is that this is easily fixable, and the song is worth doing well.