I use a Parrot CK313 which is installed into the car and integrates with the ICE. I like the elegance of it and with my previous phone (Moto V3) it was brilliant. I now have a Moto Z3 and the voice dialling has got too complex.
I also don't really like having the phone calls through the cars audio system (which has factory fit JBL power amps and speakers).
I'd prefer if it just muted the hifi and delivered calls through a separate single speaker. But I can't be bothered to re-wire it as getting the dashboard to bits is a nightmare.
It does have separate Bass/Treble settings for each source anyway (ie. changer, FM, AM and tape) all have their own. It's not so much the bass, it's the fact that telephones were never meant to have 300w amps and speaker installations at all. And it's also very audible outside the car.
My kit is integrated into the car's head unit, with microphone routed (wires hidden) to the visor. I setup my phone to bluetooth permanantly so it is available as soons as I switch on the car. To avoid having to use a hand to answer the phone, I can setup my phone to auto-answer after certain number of rings. Obviosuly I never make a phone call while the car is moving.