I really zipped through this puzzle today. I had no clue what the theme would be (and neither did any of you, I'm sure), until I'd finished the whole thing. I recognized that there was a huge amount of icky fill, but it was all very straightforward, so nothing held me up at all.
Which made the reveal kind of awesome, to be honest. I'm sure there will be some out there in the NYT blogging world who will say it wasn't worth it. To me, it absolutely was. 62A: Old rush participants ... or a three-part hint to what can be found in this puzzle's grid or clues (FORTYNINERS)... or parsed a different way, forty-nine Rs.
Let's take a moment to appreciate the artistry here. Yes, there are 49 Rs in the grid, but even better, every single across answer and every single down answer has at least one R in it. And then, there are 49 Rs in the words that make up all of the clues. I may have miscounted, but I think the 49th is the R in Across. That's attention to detail.
Then, the two long theme answers, MARGARETFARRAR and REARVIEWMIRROR, each have 5 Rs, while the two shorter theme answers, RIGHTASRAIN and FORTYNINERS, each have 2 Rs. I like the symmetry. And by the way, how about the clue for 46A: Where you might see the word AMBULANCE behind you... I really enjoyed that.
Okay, so there was a price to pay, and it is a fairly hefty one. AFR RRS RCA NCR UAR ISR GRE GRRS SRO RUR ARG REI NPR ROY RWE AARP NRA, just on a quick glance through the grid. And even the longer stuff, such as BADPERM, is pretty iffy. And hey! MRED shows up yet again!
1A: Gooey campout goody (SMORE) gets an A-, because who doesn't love that stuff? And my favorite clue-answer pair is 22A: Prime oyster season (RMONTHS). That's quite a way to shoehorn an R into an answer!
So, for me, at least, I give it a thumbs up. It's way out there for a NYT puzzle, and I like the variety.