How TSL applying the BGM as SoundFX is very intriguing; particularly with al_jazz- the BGM that played inside the NS' Entertainment Promenade. Definitely something that K1 don't have, and surely is an improvement from the former.
Edit: Just figured this out- ambient sounds and background music are two different things but is similar. It seems K1 have them too, it's just that they don't have the variety as TSL does.