Apart from going to Silverstone a good few years ago, where the sound was absolutely awe-inspiring, I only watch this on TV. The sound was never reflected properly on TV anyway, so I don't think it matters so much.
For people at the live event I'm sure its not the same, but that's a miniscule percentage of the overall audience. At least now people track-side can probably hear the PA.
The advance in engineering is well worth it, I think, but I wouldn't be surprised if there aren't manifold changes pending to try to get some of it back.
The sheer power of a single engine sparking up in the pit-lane, and then a full grid setting off was one of the most memorable experiences of the whole day. But I think I would still prefer to see the pinnacle of motorsport engineering on the grid.
That said, I wonder what Formula-E sounds like in person - probably harder to sell tickets to that. From Bernie's side, if you can't fill seats, its harder to sell TV rights. The vast majority won't care about propeller-head achievement if the overall experience is diminished.