I could have sworn I saw a post with all the details of the immersion set, and that there was a DVD-A. Guess I was mistaken.
Anyway, the reason I brought up the subject was that, like most others, I've had the 4.1 bootleg DVD-A for a number of years and was wondering if I should drop the coin on this set, solely to get a higher-fidelity version of the Parsons quad mix. From the comments I've read in this thread, I don't feel compelled to try it. I'm intrigued by the 4.0 "authentic" quad mix but not if it has less bass than the 4.1. Aside from the noise on the bootleg, I love the balance the way it is. I don't have an interest in any marbles, scarves, coasters, deck of cards, etc. so I think I'll spend my $150 somewhere else.
Of course, any mix that duplicates bass in the subwoofer channel will have 'more bass' .... but the 4.0 is hardly lacking in that department. A properly bass-managed surround setup redirects the 4.0 bass to the sub.