Hi Benedict, since you asked ..
I am generally not a fan of using MIDI files, because most of them are designed for GM soundsets, that as a rule are pretty weak, and it seems to me (just my opinion) that the arrangements in the MIDI files are built with this limitation. For example you won't find the MIDI files playing long sweeping, evolving pads, because they don't exist in the GM palette.
A good example of how this sounds GM midi - is the drum track, which I don't feel suits the mood of the song.
Now look at your own brilliant sound design skills, you know how to make big, fantastic sounds, and I feel they are wasted by a MIDI file designed for GM sounds.
That's the critical part out of the way.
Let's talk about the sounds.
The guitar sounds in here are absolutely brilliant - I have no idea how you did it but major kudos!! Extremely convincing, I would have sworn they were guitar samples.
The EP is also perfect. (and the EP line in the MIDI file is actually really nice)
So are the rest of the sounds. I think I would have used one of your vocal sounds for the vocal melody but I'm sure whether it would have been any better or worse.
My suggestion would be; replace the GM-sounding tracks (not because of the sounds but because of the arrangement) with your own lines, I know you have the talent to do this. I bet you could make the track sparkle just by replacing the drum track with something less busy, using bigger drums, and with some more interesting transitions.
Another suggestion (and you may not want to do this) is to showcase more of your sounds. I think it would be interesting if you added phrases of your own that did not exist in the original song, where you feel they add your own character to the original song.
You have a flair for orchestral arrangements. I'd really like to hear the Benedict style on this track here.
Just my 2c.
cheers
Raymond