While much of Apple's recently released OS enhancements in Snow Leopard are fine-tuning rather than new features, one of the advantages of upgrading is to reverse the bloat of software installs.

As Apple is keen to point out - 'Snow Leopard takes up less than half the disk space of the previous version, freeing about 7GB for you - enough for about 1,750 more songs or a few thousand more photos.'

Macworld reader Jayson Brinkler was surprised, delighted even, then to discover Apple's estimation was some way out.

"I purchased and installed Snow Leopard today and was interested to find that I did not get back the 7GB of hard drive space that Apple claimed that I would get back - I got 33GB of disc space back!" Jayson tells Macworld.

"Before installing, I had 325.5GB free space on my 500GB internal drive. After install I had 358.73. I don't know if my install disc has performed magic or it has deleted files during install, which is unlikely, but nevertheless, it is intriguing."

As an owner of an anorexic MacBook Air, I'm hoping installing Snow Leopard will perform similar magic on my modest 80GB hard drive.