I wouldn't expect anything too dramatic from toothpaste or over the counter whitening products. While most will give a whitER result, they are often short lived.
Also, I would not expect much in the way of sensitivity, but everybody is different (some people even have trouble with certain brands or flavors of toothpaste) and only from trial and error would you find out if you were sensitive.
We sell this toothpaste and I use it from time to time. You may experience a bit of whitening, but I wouldn't expect dramatic results. For that, you would need professional teeth whitening. I did not experience sensitivity with Supersmile and I have not heard of anyone else doing so.
Hope this helps!