City 03-08 has idsi engine(except Steermatic) where as the new city has ivtec enigne.
idsi vs ivtec
1. idsi engine is more economical than ivtec (You can google to find it out). By that i don't mean that vtec is not economical at all.
2. ivtec is more powerful engine than dsi. This means that both engine having same displacement then ivtec will produce more torque than idsi.
Further features like Brake System is far better in the new City as they have included ABS. Now, It all depends on your requirements which one you like. Mostly mechanics don't understand new systems thats why they say that previous models are good.