Will Affleck Hit Replay?

With all due respect to Groundhog Day (and I think it's one of the best movies of the Nineties), Replay is not just a rehash “with more angst”. First, it came out before Groundhog Day by a considerable margin, 1986 (not 1989) being 7 years before Groundhog Day's debut in 1993 (though I know no reason to think Replay was an influence on it). As you said, it was optioned for a film and not made, but in between, Brad Pitt and Julia Roberts were considering it as a vehicle, so it was a project with some juice for a while. It also won the World Fantasy Award and was a modest bestseller which has been reprinted several times. If you look at the Amazon reviews for it, you'll see that it has an ardent following (of which I'm obviously a member).

While not a comedy (though it certainly has witty moments), I wouldn't call it a angst-filled book; it covers a wide emotional range. While it's best to know as little as possible before reading it, I will say (POTENTIAL SPOILER) it, like Groundhog Day, has multiple replays; but these happen over decades, not a single day, so that it's a more expansive, less claustrophobic story. It also covers the period 1963 to 1988, so it has a historical flavor that Groundhog Day lacks. The important respect in which both are alike, though, is that they both turn the rare trick (along with the last act of Our Town, perhaps) of making life seem larger than life, which is not just a neat trick, but a profound one.

So I don't see this as some kind of step down for Affleck at all; rather the reverse. It could be just as fine as the ones he's already directed, or better; the potential for a challenging, memorable movie is definitely there. Of course, that was true of The Time Traveller's Wife, too,
which for my money, at least, did not met the challenge. It's all up to Affleck; if he can do it justice, then it will as much a classic (though a complementary one) as Groundhog Day is, even without a Bostonian connection.