At $30,000 for a 2016 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.
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 otherSUVs. The HUD-heads up display is a nice feature where I keep the speedometwrfloating low on the windshield.
At $29,000 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.