His talent, and that of his orchestra, is difficult to question. Certainly, as the saying goes, nothing succeeds like success! Is he as "good" as Nigel Kennedy, or Yehudi Menuhin, or Stéphane Grappelli? That's such a stupid question that no-one with any sense would ask it! For one thing, what criteria would you use to measure it?
The question is, do you like what he does? I don't, personally - it's just too smooth and predictable. There's never really any danger of anything going wrong.
I much prefer fiddlers like Charlie McKerron, Duncan Chisholm, Aly Bain et al. The master, Dave Swarbrick, is sadly no longer with us.