Never without orchestration mixed in.
But, really... what's your point? MIDI is actually sometimes a better option than live instruments.
"Sometimes" doesn't cut it.
The fluent pieces of Aion: Tower of Eternity by far sound better than the Pokemon X/Y tracks, and Guilty Gear also has an edge over the Midi-fied guitar riffs in the video I posted.
You are aware that what I said also means that orchestration is only "sometimes" better suited for a track than MIDI, correct?
I'm pretty sure there's never any MIDI guitar in X&Y (read: I know there isn't). The only MIDI used is for the parts of tracks that are better suited with it, just like in the Galaxy games and Skyward Sword, all three of which have ridiculously awesome music. I don't think you realize that both orchestration and MIDI have their own unique benefits, i.e. strengths over the other.
Also, I'd just like to point out that Metroid Prime still has one of the most riveting soundtracks ever composed to this day, and as far as I know, it's pure MIDI. Just sayin'.