I don't know if the Beosound 1 is better, I just found it sounds warmer and more detailed. I can only say that for my taste the "new" Beolab 4000 sounds awful (worse than my BL4's). They may have better Bass, but my BL4's sound MUCH more natural.
For my taste the BS1 sounds very nice!
With the BL4000's bad sound you don't get any good B&O speakers under 3000€, which is sad.
My next speaker will be the Kef iQ9!