Импалу не трогал сам, а вот тестеры edmunds.com трогали и написали следующее:

Review of the 2015 Chevrolet Impala

With its appealing blend of style, space and available V6 power, the 2015 Chevrolet Impala is a force to be reckoned with among full-size sedans.

Pros Serene and quiet ride; sleek, feature-rich cabin; big backseat and trunk; excellent crash test scores.
Cons Four-cylinder engine lacks oomph; touchscreen interface can be slow to respond; a few subpar interior trimmings.

What's New for 2015
For the 2015 Chevrolet Impala, the hybrid-powered eAssist model has been discontinued. All models get a new 4G data connection with WiFi hotspot capability. Also, a gasoline/CNG bi-fuel model makes its debut.


Review of the 2015 Honda Accord

The 2015 Honda Accord earns top honors in the midsize sedan class with its well-rounded mix of excellent packaging, superb fuel economy and rewarding performance.

Pros Roomy and high-quality interior; refined and efficient powertrains; quick acceleration; responsive handling; generous standard features; available coupe body style.
Cons Many desirable features available only in upper trim levels; non-split-folding rear seat; finicky dual-screen infotainment system.

What's New for 2015
Apart from a minor shuffling of standard features, the 2015 Honda Accord sees no changes.


Не вижу где здесь импала конкурирует с а6.