This puzzle has it all. I love the presentation of the quotation in a cascading set of shaded four-letter words. Better, each word is actually hidden in another unrelated word (well, mostly - LIFER and "life" are from the same root). The movement of the words from NW to SE brings to mind falling rain. Very nice.
Certainly because so much theme is crammed into that diagonal, there are a number of 3-letter glue answers in the middle. But they are surprisingly minimal (partial HOI, abbreviation ORU for Oral Roberts University, suffix ISM). You also get the remarkable pair of ten-letter answers NONSTEROID and RUMORMILLS running through three theme answers each.
I also love 1A: "Dante Symphony" composer (LISZT). An unusual composition to reference, one which I've never heard. I would have expected a Hungarian Rhapsody or Liebestraum. For the wonderful Scrabbly density of his name, I'm giving him an A-.
What's really nice about this grid is the very open areas in the NE and SW, with only one theme answer each, which allows for some nice work. How nice is it that LONGFELLOW and FITZGERALD are the same number of letters? Any reference to the divine Ella is a win in my book, especially when her last name is so rare in crossword grids.
It's impressive that Mr. Stulberg matches these long theme answers with a second stacked 10-letter answer. 60A: Variety of sherry whose name means "little apple" (MANZANILLA) is excellent, especially because it reminds me of The Gondoliers. "Old Xeres we'll drink, manzanilla, montero..."
I'm inclined to overlook the proliferation of 3-letter answers at the corners. AFLICKER is mildly annoying. But whatever you might think of the puzzle, I'm sure it didn't cause you to go "ZZZ..."