Thanks a lot Mycle & Luben for your valuable feedback. One more thing I'd like to know that AF-S 18-105mm VR Kit lens or EF S18-135 IS which lens is better? Is it EF S 18-135 as it provide more zoom than Nikon 18-105??
Which lens is probably better - i don't know. A direct competition is diffcult, depending on the camera where it is mounted.
At photozone.de you will get some informations and performance results of many lenses.
Here the Canon:
http://www.photozone.de/canon-eos/776-canon_18135_3556stmis
Here the Nikon (tested on D7000):
http://www.photozone.de/nikon--nikkor-aps-c-lens-tests/634-nikkor181053556vr
The Canon lens provides a larger focus range (30mm more tele).