I have been using the Quattro 4.0 for well over a year, and used its predecessor, the Quattro for several years. The 4.0 was issued to me as part of my patient kit and I use it constantly. It is paired with my iPhone, and landline phone. The detachable microphone does come in handy and the improved version of it comes with both a lanyard with a docking station for the charger as well as a magnet so you can clip the microphone to a piece of clothing. Much easier to use.
I find that the 4.0 has some great features such as remembering multiple devices and the ability to recharge while in use. Voice calling, etc. are also included. The wall charger works equally well from 100-240 volts, and either 50 or 60 Hz. All you would need to do is to find the correct adapter plug for the wall socket.The power cord itself terminates in a USB plug so if your car phone charger has an extra slot you can drive, listen to your phone and charge at the same time.
I have no experience with the Phonak Roger, sorry. Please let me know how else I may be of service.