An enjoyable puzzle that turned out to be a lot easier than I'd feared after last year's Search. I agree the clues were nicely balanced between easy and somewhat tricky, and clue surfaces on the whole were rather good. I quickly saw what to do with the grid before attempting to make sense of the extra across phrases, a couple of which I'd misidentified anyway. And the grid construction, with all real words in both grids, is impressive.
I do have one minor niggle, however. The requirement to write the author below the grid seems totally pointless. If solvers fail to get the theme they'll fail to complete the blank cells correctly. What is the point of asking them to interpret 'traditionally' correctly in their choice of one out of two authors? In general I think boxes are appropriate where it's necessary for the solver to show fuller understanding than can be shown by the correctly filled grid alone, but that's not really the case here, especially as in one sense the placements of the letter pairs in the extra words are not thematic.