Horace here, coming to you live and direct from Utrecht, The Netherlands!
The theme today is "'ST' changes to 'D'," resulting in new phrases clued to make sense. "19A: Romantic night in Kentucky?" is answered with BLUEGRASSDATE, and "41A: Counterfeit Dodge?" is FALSEDART. There are four across and two down, which I like.
What I don't like is MASSAGER (17A: One rubbing you the right way?). "Masseuse" fits in the same spot and is quite a bit more common a term. And can we talk for a minute about SKYEY (25D: Brilliantly blue)? I find that a bit startling. The rest of the iffy stuff (ISH, ELHI, ETTE, UTE, SYSTS...) I am a bit more used to.
I like much of the other (not obviously bad, if you know what I mean) non-theme fill, and I enjoyed many of the clues. 24D: Lengthening shadow? (BEARD), 51A: "I thought you had my back!" (ETTU), and 34D: Taken for a fool (PLAYED), for example.
There were several names I was not familiar with - TBOONE (60A: Pickens ...), HERSHEL (7D: ____ Greene...), ARI (36A: Gold ...), OPRAH (9D: TV personality...) (KIDDING!). And I guess I was only luke-warm on the theme. Maybe it's just that I've been up for something like 36 hours in a row, but I'm giving this a so-so and then we're going out for some traditional Dutch fries and a beer.
Over and out.
p.s. 1A: Collateral, of a sort (LIEN) - B. Solid.