The Omni was probably a better car. I had a Chevette for 6 years. My wife was given one as a graduation present, so I was stuck with it. It had the more powerful engine but was an automatic, and was plain horrible, and didn't get very good gas mileage. When she first got it, it was improperly tuned and was getting 25 mpg on the highway. I couldn't believe how bad it was so I checked the tuning, it was way off. I fixed that, which helped some.
I still had my '73 Nova, so we drove the Chevette to work usually to save gas, a bit. I traded it in on a Dodge Caravan which at least had the 5 speed.
