Personally I haven't felt any issues with torque. My C3 has the same kerbweight as the C4 Cactus (for a bigger car, the Cactus is super light!), though I have found Citroen's gear ratios are a lot higher than my old car (accounting for the final drive ratio and wheel size difference, my old cars 5th gear was very similar to C3's 4th gear ratio) - I suspect to get decent high speed economy, with only five gears.
At 30 you are only just into 4th gear territory and 40mph is 5th gear.
As I said earlier, my main gripe with the engine Is the harshness of it, purely for the driver.
Performance wise, on boost, it has shown up a few boy racers
...and if Skodas PR team is to be believed
....