Oh, but of course!  I honestly wasn't quite a 'diligent' fan of either, but was pleasantly fascinated when first came across years ago.  Aside from a handful of songs, I usually get tired of the same old holiday tunes, too… to mix classical and a more rock/electronic style like TSO does?  Loved it.  One of favorites remains Christmas Canon, and their version of Carol of the Bells. 
I was actually lucky enough to notice by chance that they were doing a 'final' tour of their concert "The Last Christmas" last December, and it stopped in the next city over, so that was our xmas gift to each other and my first time seeing them live.     Have you?