I have almost 30,000 miles on my Caliber and it has been an excellent car. I've seen some of the other Caliber reviews, where the owners had immediate problems, all I can say is that my car has been outstanding with zero issues. I've owned seven different Chrysler/Dodge/Jeep products over the past 20 years, and they have been fantastic cars. Nice cars, great prices, and the reliability has been outstanding.
The fuel efficiency is my favorite feature. I've been getting very good mileage, averaging 31 mpg, and that is with both city and highway driving. My car has the 5-speed, so that obviously gives me an mpg advantage.
I rated the interior/comfort as both 8. The reason: I felt the interior could have been nicer/upgraded. They seem to have done that for 2010/2011, since the newer Calibers have a much more stylish and refined interior.