There’s a ton of debate about whether they really do sound like the real thing. In my experience, amp simulators come extremely close, so much so that it does actually make sense to invest in one of these systems both for touring because of the convenience and ease of use. In the studio, though, where you’ll likely have several options available to you, it really comes down to taste and playability.
The choral voices are there in support of a bunch of Da Vinci Code malarkey about secret codes that Bach supposedly was hiding throughout the music. I’m totally uninterested in this idea, whether or not it’s true, but I am intrigued by the possibility that Bach was quoting or adapting pieces of Lutheran chorale tunes. Morimur superimposes the chaconne with the chorales that it’s supposedly quoting. Who knows whether this was in Bach’s mind or not, but it sounds great — and ultimately, that’s the only thing that matters for music.