We love recycling around here, so this cross-referenced, letter-borrowing puzzle was right up our alley. The theme answers were perfectly symmetrical, which I find kind of amazing, and the theme answers, while not really scintillating, were solid enough. Our favorite over here was NATHANHALE/ETHANALLAN.
SWATS (5A: Tries to beat the buzzer?) was amusing, and FLUB (43A: Screw up) got a chuckle, as did NAILEDIT (28D: Sarcastic response to a fail). I dropped in "eskerS" at 11D: Glacial ridges (ARETES). D'oh! They meant the kind of ridge that's cut away, not the kind of ridge that's deposited. Sometimes, I guess, it's possible to know too much about quaternary geology. :)
31A: Order to go (MUSH) was tricky, and I could not think of KEYUP (19A: Energize) for the life of me. I kept thinking of "pep up" and even "gin up." Hmph.
The fill was pretty solid, without too much crosswordese. Well, ok, maybe ODEA and ORES, but they don't GRATE too much. Good cluing (69A: You can lend one without letting go of it (EAR)), interesting fill (FIGMENT), and a Gilbert and Sullivan reference (MIKADO), what's not to like?
My favorite clue/answer - 117A: Sun spot? (SKY). Hahahahahahaa! That's some quality work right there.
Well, I'm not so high on this theme. So they're synonyms that use the same letters. Not enough for me, although I see how the amount of crossing answers adds a level of difficulty to the construction. Truth is, the answers themselves just aren't interesting enough.
My grid (in pen) is a mess of mistakes. I tried erE at 32D: Word before "before" (USE), thinking it was a clever way of talking about archaicisms. But no, it was just a random word before "before." I also tried Pac at 44A: Fund-raising org. (PTA). WENTSolo was corrected fairly quickly to WENTSTAG.
I do like the odd letter collections of CDTOWER, SURFNTURF and MODELTS. And EGBERT went in right off the clue, so there's useless knowledge for you.
I think my standards were raised unnecessarily high by the last several days. Ah well. Over to you, Horace!