That is a pretty a good performance of the Rubinstein, i must say. I did used to play this, but i doubt if i could nowadays due to lack of practise.
I have never played the Thalberg, but a quick look a the score indicates that unless you can easily stretch a 10th, it might be physically impossible for some.
On balance, i would say the Thalberg is more difficult (perhaps ultimate), but i no longer have the pianistic equipment to find out.
Thal