Mr. Kubelik's artistry is of the most remarkable kind. He is not a deeply moving player; he has not the power of touching profoundly and immediately the hearts of his listeners nor of laying hold of the inner mystery of the greatest music. There is something aloof in him as he plays it; yet few have the power of so ravishing the senses with the sheer beauty of his tone, the charm of his cantilena, the elegance and ease with which he masters all the technical difficulties of what he is playing so that they no longer suggest themselves as difficulties. Octaves, thirds and sixths drop from his instrument in a tone of honeyed sweetness and oily smoothness; not a large tone, but one of indescribable roundness and purity; his runs and passages of all sorts are as pearls from his hands. There is something of feminine grace and charm in Mr. Kubelik's playing, and he seldom compels by its authority or stirs by its passion and virility, but in its way it is wholly delightful.
I found a copy of the recordings. From the early 1930's there is a lot of analog noise and scratching, but you can tell the that the guy, even at about 60 when this was recorded, was good.