Mountain Lion is still a cub, at less than a week old, but more than half of Macworld readers have already upgraded to the new operating system, according to a recent poll.

Out of 549 respondents, 52.5 per cent said that they have upgraded to Mountain Lion and that it works well, but 2.7 per cent have said that they had problems downloading the new operating system.

A small 2.6 per cent of Macworld readers listed their reason for not upgrading as down to the lack of the Mac App Store on their Mac, suggesting that the majority of respondents are already running Snow Leopard or later, the first OS X to get Mac App Store. Mountain Lion is currently only available for download from Apple from the Mac App Store, so those without it are left out of the loop at present.

More than 20 per cent said that they are waiting for a few weeks before downloading Mountain Lion, presumably hoping that any teething problems will be ironed out by then.

A total of 13.8 per cent of respondents are happy sticking to the OS X they’re already running, rather than upgrading Mountain Lion.

Many of those who haven’t downloaded Mountain Lion are unable to due to Apple’s hardware specifications. “Sadly, my little MacBook is only just that little bit too antiquated to run Mountain Lion,” said GrumpyGiraffe in the Macworld forums, who seems content running Lion for now.

A second forum member, though, is not so happy: “My two year old Mac mini server used as a desktop replacement cannot be upgraded,” wrote SwissMac. “I was going to upgrade to an iPhone 5 when it comes out but if iOS 6 needs Mountain Lion then I’ll be stuffed… Not pleased about that at all.”

Apple has announced that it Mountain Lion has been downloaded more than three million times since its release on 25 July, making it the most successful OS X in the company’s history.