I reserve the right to change my mind, but I think this is a good idea.
I generally hate loud sounds, especially high-pitched loud beeps that seem to be more and more common. I don't know, maybe I'm just a bit autistic, but whatever. I've thrown eggs at honking cars. Hell, I'm proud of that: They were honking at the sanitation workers picking up trash, for crying out loud! And I tried talking to the honkers first. They told me to get stuffed. F*ck 'em. And then there was that time I slashed the tires of a car whose car alarm kept me and my neighbors up, literally, for hours.
(Did I just admit that? It was years ago. Just two tires... and I first called the police a few times, who did nothing. And I did, after releasing my anger on the right front and rear tires, leave a note making very clear that this was most definitelynot some "random" act of vandalism.)
This new siren is half the perceived volume (10 dB less) of a standard siren. That's great if you happen to be pedestrian or bike. It's low frequency, which is great if you happen to be in a car. If this means less high-pitched siren use, I'm all for it. If it's just another sound to add to an already too loud city, I'm against it.
And who knows... maybe people will actually get out the way of emergency vehicles. That would be a change.
But just for fun, I wish officers would have to put a quarter in a machine on the dash to activate "The Rumbler."