I have a 1.4/Auto Dart and I have been right around the EPA numbers (I have about 17,000 miles). My lowest tank ever was 26 MPG, and my highest was 36 MPG.
The 1.4 really depends on how you drive it. If I wanted to be extra careful, I am sure that I could be get it above 40 on the interstate (keep the speed at or below 70, windows up, no A/C). The same is true in town, if you drive carefully, getting 30 in the city is possible. The problem is, that isn't any fun. When that turbo gets going, the car really moves. Unfortunately, so does the fuel gauge.
There doesn't seem to be much differnce in the fuel either. 91 is recommended, but 87 is acceptable. 91 seems to get a little better economy, but the $/mile comes out about the same.
There is some sluggish acceleration at points (typically at low speeds), but once you learn what causes them, they are easy to avoid (especially with the Autostick). If you get a test drive of the 1.4, accelerate from a stop to about 15 mph then coast for a second and try to accelerate again. You should be in second gear with very low RPMs. That is the most severe sluggishness I have had, but a quick down shift with the Autostick (or keeping it in 1st to begin with) completely eliminates that problem.