Cranky, as in "screwy" video cards, "insomniac-like power-sucking" sleep mode and not playing well with third-party RAM, according to Gizmodo's Matt Buchanan.
The video cards? When asked about the issue, AppleCare UK stated that company reps are "aware of the issue and are investigating. At present we do not know if this is a hardware or software issue and have been advised not to offer customers exchanges until the issue is better understood." Update: The Inquirer just posted a lengthy analysis of this issue.
The sleep mode? Several issues: In one instance, after going to sleep, the notebook will wake up 30-60 seconds later, then go back to sleep, repeating the cycle until the battery is dead. Another instance is putting the Macbook to sleep only to wake up to a dead battery in the morning. A third instance is where the damn Macbook just won't wake up.
(Buchanan's solution: reset the memory and controller chip. This only works for some, though, and customers have reported that Apple offered to swap out their notebook entirely because of the problem.)
And the memory: Third-party memory upgrades, even from reputable companies such as Crucial and OWC, are making new MacBooks go bonkers -- as in crashes, lock-ups and an assortment of other abnormal behavior. Apparently, reinstalling the original RAM returns operations to normal, as does purchasing the Samsung-manufactured RAM directly from Apple.
Either way, none of these problems are widespread -- they're all fairly spotty, according to Buchanan. Perhaps a firmware update will solve several of these issues, but who knows.
Got a new Macbook? Has it gone wonky on you? Tell me your story in TalkBack.
Update: Engadget has its own thread on the issue.