I do not regret the purchase.
I may have made can not shoot a lot of photos with what I've seen, surpassed in terms of sharpness, but everything that has ever made the old kit lens to pass. Chromatic aberrations I could not discover yet, the old me have this always very disturbed, so that it eventually barely came into use.
The new lens solves my 50mm 1.8 lens from the favorite. Its picture quality is still better, but sometimes mans may well yet comfortable and do not want to be solely dependent on the good old foot-Zoom by the fixed focal length nunmal brings.
The image stabilizer works quietly (you can hear not) and reliably how many stops he gets out, however, I can not judge. Etc. shutter speeds of 1/20 at 55mm but are probably realistic. Mind you, the 400D still has the crop factor of 1.6. After a rule of thumb 1 / focal length so is the freehand shutter speed around 1 / 80s. Summary: 2 Stops gain I would now classify times as possible. Who wants to shake even less, to swallow ne diazepam ;-)
All in all a nice objective for the budget conscious. Sure, you can spend more, the limit upwards is indeed quite open. But for ambitious amateur photographers, it no longer has to be. In addition to the aforementioned and undisputed 50mm 1.8 - lens this one is probably the cheapest in the Canon range. Much objective for the money.