The Broadway is an amplifier that I enjoy hooking up to my full sized headphones. It sounds fantastic with the Susvara, HE1000se, Diana V2 but most of all with the Diana Phi. With the Phi it reaches a level of sonic bliss that is hard to find, especially since the Diana Phi is such a critical headphone to pair with.
I think the battery powered design is brilliant, and it certainly brings a lot of advantages compared to regular amplifiers. It removes polluted DC power from the equation and keeps the signal clean. The Broadway range are two very unique products, and I think many people could enjoy them a lot.
Personally, I would take the Broadway over the Broadway S simply because at home I exclusively use over ear headphones.
For its outstanding sonic qualities and the ability to handle all my headphones with ease, I am putting the Broadway also on our Best Amplifier list. Absolutely deserved.