A:Answer Hi Garyla75, It depends on your preferences. One of their differences is the Bluetooth profile. NWA35B supports Object Push Profile (OPP) Bluetooth profile. You may compare them by visiting the links below:
https://docs.sony.com/release//SPECS/NWA35B_mksp.pdf
https://docs.sony.com/release//SPECS/NWA45B_mksp.pdf
Regards,
Vincent