AG rebus, four long entries containing two rebi apiece. I must admit, I've thought about this for a few days, and I still can't come up with the rationale behind the theme. AG is the elemental symbol for silver, but is there a reason to put two silvers into each theme answer? Perhaps there's some clever phrase, like TWO-AG or AG PAIR that I don't know about? Most curious.

My preference for rebi is to have some raison d'etre, a revealer to explain why certain letters have been rebusized. (Rebified?) CRUSHED ICE was one that stuck out to me a while back, for example. So I would have loved to have one of the answers somehow give me an a-ha moment of "oh, THAT'S why two AG boxes are shoved into each long across answer!"
Some nice "theme answers," my favorites ON AGAIN / OFF AGAIN and AGREE TO DISAGREE. Then again, there's something oppositional about these two entries that made me so badly want the others to be equally oppositional, for consistency's sake. Ah well.
I liked some of the fill, like FLORISTS and especially HASHT(AG), the latter even better since it incorporated one of the rebus squares. I really like when rebus squares get featured, both in the across and the down directions.
Conversely, I really don't like when rebus squares are integrated into subpar answers. Any sort of variant is generally to be avoided, so (AG)ISM (usually AGEISM) is unfortunate. Every has their own preference on what type of crossword glue is the worst — for me, variants are right up there. I'll usually do anything to avoid a variant.
There will probably be questions about ARNIE as a [Noted "army" leader]: that's Arnold Palmer's legion of fans in the old days, nicknamed "Arnie's Army."
The clue for FLORISTS was mystifying, too, at least until I figured out that the "glad" of [Glad handlers?] is talking about the gladiolus flower, which it seems is sometimes called a "glad."
I'm pretty sure there isn't a rationale for why there are two AGs in each theme answer, but I'm really curious now if anyone can come up a phrase that would have made for a perfect revealer. ADDED NOTE: I really like Matt Gaffney's suggestion: "FILL" SILVERS!