For the most part, I think they are both quality vehicles and it's going to come down to personal preference.

Test drive them both...or even better, rent one of each for a couple of days. See which one you like better.

For what it's worth, I just bought an '06 Prius after having two Honda Civics and a VW Rabbit in the past and I love the Prius. I didn't get the NAV, but did get the Vehicle Stability Control (an option I don't think is available on the Civics yet), the SKS, and the HID headlights. I'm very happy with my option package.

2006 Barcelona Red Metallic Prius (HK #6)
February 8, 2006