At US$43,,000 for a 2017 the quietest and smoothest would be a Buick Envision Premium l. With it's Hyperstrut from suspension and among the twin-clutch AWD it achieved 55.5 mph in Consumer Reports emergency test or on par with Porsche Macan and Jaguar F-pace. Along with handling it has the best braking for it's segment according to Car & Driver testing. It is also quieter than a Lexus RX according to C&D. This same cuv at US $49,000 before discounts offer all electronic safety features including articulating headlights that are also adaptive high beams, cross traffic alert when backing up, vibrating safety seat, forward and backward collision alert and stopping....
It has real leather seats with heat front and rear, along with heated leather steering wheel. The tri-zone climate control will have you not freezing yourself while trying to keep your rear passengers cool like most of the other SUVs. Unlike most at this price it has cooled front seats. The HUD-heads up display is a nice feature where I keep the speedometwrfloating low on the windshield.
At a discounted $33,000 the Envision is over $10,000 less expensive than a Lexus NX200T where some of the options are not available at any price but are offered on the Buick.
The Cadillac XT5 is the next step up from the Buick and can offer similar features.