The 5151 Podcast, Episode 2: Why are OG Explanations so Awful? https://tinyurl.com/znbw33v8Corrections / errata:
-At one point I say that the GMAT "hasn't changed" since the introduction of the IR section in 2012. This isn't entirely true, though I stand by my statement that any OG after 2012 is fine.
In retrospect, though, I should clarify: I do strongly feel that the official GMAT exam has evolved and increased in overall difficulty since then; in particular, the difficulty of the Verbal section increased noticeably sometime around 2017.
Of course, there are also the rumors that the GMAT online Quant questions are trickier and wordier than their test-center counterparts, a statement with which I happen to agree (I scored Q50 on my last test-center exam, but "only" Q48 on the GMAT online).
However, I do stand by my claim that all the editions of the OG since then are equally helpful (other than slight differences in the number of questions per edition), since the difficulty level of the OGs themselves has not changed, despite the actual exam having increased in difficulty.