What does that mean? Is the binary format already in use?
0.2.x versions worked with binary format. Now peer communication is done with JSON format.
Ah, I see.
Still, I strongly advice you to add another layer (compression whatever) instead of using a binary format.
From an engineering point of view, it's proven to be more reliable, secure and flexible. Especially when it comes to something sensitive like a currency system, please do not sacrifice security in favor of cool speed. I could live with 700TPS as well. Layers underneath NXT will evolve further and will eventually provide speed-ups in the future.