Both of these engines are durable and can last a long time if properly maintained and serviced. Honda Acoords are pretty legendary for their reliability. If you get a previously owned vehicle it's important to find out if the car has been maintained in accordance with the service scheduled and not abused/neglected, for either the 4 or 6 cyl model. Have an independent mechanic check out any car that you're seriously considering to purchase. Whether to get a 4 or 6 cyl model will depend on your preferences and needs. If economy and cost of operation is most important, the 4 cylinder model will of course be more fuel efficient in terms of operation and more economical to service. The acceleration is adquate for everyday driving. The V6 is more refined/quieter at higher speeds and under acceleration. V6 models will tend to have more comfort/convenience features such as leather upholstery, sunroof, etc. than most if not all 4 cyl variants.