Of course, it depends on the type of blur. If it's movement in the subject causing blur, VR systems don't do anything to help that.
The blur wasn't caused by movement in the subject I was shooting landscape. It looked more like if I didn't get the focus very well. Maybe there was some movement because of shooting from hand but I expected a better result.
Do I have any chance to shoot sharp pics indoors if I choose the sigma?
I don't want to loose the +100mm focal length which the sigma offers...
Of course you can shoot sharp pictures with the Sigma. If you're shutter speed is a bit lower than ideal then you will still get better with practice. But in bright light I don't think you'll miss the VR.
Why not get into a shop and try one on your camera?