I guessed the theme as soon as I read the preamble, so I knew what to look out for, but it was many hours before I got sight of what I was expecting. The downside of guessing the theme early is that there is no reward at the end for all that slog, and it was a slog. The across clues were fiendish to unravel, in some cases even when I knew both answers. I agree with Flocko in that respect. On more than one occasion I had a wrong answer that was justified by elements in the clue, which ruined my chances of solving the other clue, or a definition that satisfied one answer, only to find I had to split the definition to justify another answer. In several cases the paired clues were clearly designed to confuse and misdirect beyond their interwoven character. There were few concession to compensate for the intrinsic toughness of the presentation.
After more than three hours I had only eight answers, half of which I could not enter. I think I spent at least ten hours in all on the puzzle, possibly as many as twelve, spread over three days, and I can't say I got much enjoyment from it. The only thing that drove me on was a stubborn resistance to admitting defeat (and, of course, the tyranny of the statistics).
In my book a puzzle as tough as this should have an endgame reward that is commensurate with the effort the solver has to put into it. I can think of several Listeners from the past couple of years where that has been the case. The minor change to the grid was a slim reward. Even if I hadn't guessed the theme I would have felt the same.
Sorry, Paddock, not my cup of tea, but I grant you your paired across clues were very deftly interwoven.