The model you are looking at are infamous for gearbox problems, mostly due to Honda service centers using the wrong oil to service the gearbox and damaging it. If you are unlucky enough to get one like that, you will be looking at a hefty repair bill soon, possibly more than what you paid for the car.

IDSI is supposed to be the model with better fuel economy compared to VTEC, although some owners say the difference is not huge. Also, IDSI has lower horsepower and uses 8 spark plugs compared to VTEC's 4 spark plug.

For 25k, just get a used Myvi, or Saga/Persona if you need a sedan. It's not a Honda, but at least it won't be 13 years old.