Yes, Sony SBH56 does have the NFC connectivity.
Yes, Sony SBH56 does have the inbuilt speaker.
No. Sony SBH56 does not have the removable battery.
Yes, Sony SBH56 does have the 3.5 mm headphone jack.
The Sony SBH56 is very good in voice quality, the sound quality from the in-ear earphones is clear and sharp, and the microphone quality is also good. The recording quality of the microphone is also quite good.
The Sony SBH-56 is a fantastic accessory to have if you have many wired in-ears and headphones. It certainly turns all of your devices 'wireless'. It is a fantastic choice for those who want to step in the wireless world without an overhaul of all their wired audio products.