I don't know about you, but I don't particularly like it when an explanatory note appears with a crossword. Today's reads: "When finished, this crossword grid will have 25 things that complete a set, in the order indicated by the clues." First of all, "25 things?" I guess by "things" they mean "pairs of letters that are adjacent both in the alphabet and in the answers with bracketed numbers" and by "a set" they mean "all the letters of the alphabet repeated twice, in order, except for A, P, T, and Z." Did I miss any?
So it's a stunt puzzle. Sometimes those are good, and other times, they are somewhat interesting but filled with strained or tired fill. See: ENOL (27D: Hydroxyl group compound ), AFAR, AFORE, KMS (41A: Eur. distance measures), CAVA (9A: Vena ____ (major vessel)), and SSRS (60D: They became independent in 1991: Abbr.). Fun stuff.
There were bright spots, though. POPQUIZ (50A: Classroom surprise ) was fun, and BMWXSERIES (62A: Line of upscale German autors ) was unexpected. CONDEMN (9D: Mark for demolition ) and SINEW (54A: Muscular strength) are good words, and who can argue with CLAM chowder? As long as it's not Manhattan-style. :)
But overall, the TIAS, BCE, BRAE, and LOMB type stuff left me DOUR. I don't want to give it a total NOGO, but let's just say it wasn't my favorite.
1A: Wall Street index, for short (SANDP) - C-.
Favorite: RADIUS (40D: Wheel spoke, essentially).
Least: ALFA (2D: Letter before bravo) - Where's the "var." tag?