I wouldn't mind glass like this on our bedroom window since I am a light
sleeper and just about anything from birds to motorbikes on the road
200m away wake me up.

Remember it's all structural elements, not just windows, that need to
be designed to supress sound.

Yes, I've also heard large gaps in DG required for soundproofing, but
smaller gaps for improved thermal insulation. Obviously well fitted DG
is better than single glazed sashes - but beyond that the payback may
be small.

You might be better with thick curtains, thick carpets etc. to dampen
sound within the room.