Good for Kavakos. To my thinking, Heifetz is a hard act to follow, but not impossible.
I heard the Sibelius performed last week by an outstanding flautist, DB of the Met Opera Orchestra. As much as I appreciate his pushing the envelope, I was reminded how very different the flute and violin are in terms of nuance and expression. It does not seem feasible to recreate the architecture we hear in the finest readings of this piece on any other instrument than the violin.
http://www.artsjournal.com/slippeddisc/2013/04/who-owns-the-sibelius-concerto.html#comment-111906