Rather bizarrely, Macs now support Microsoft Exchange by default while Windows doesn't. But there's more to Snow Leopard than support for Microsoft's collaboration and communication system - which is just as well, given that few home users give a monkey's about Exchange.
iChat AV does a better job using less bandwidth than before, PDF handling has been improved to make selecting text in multi-column layouts much simpler, and networking has been cleverly tweaked so that a sleeping Mac will wake up when files need to be shared and nod off again when it's no longer needed.
The most dramatic new feature is QuickTime X, a major overhaul of Apple's media player. It can use hardware acceleration for smoother playback, supports HTTP Live Streaming and provides easy video capture and uploading to YouTube or MobileMe. You also get iPhone 3GS-style video editing and a much less obtrusive interface.
Windows 7 gets better multimedia too. Media Player supports more formats including H.264 video, and there's a nice feature called Play To that enables you to send media to other devices such as the Xbox 360. Cleverly, Play To will convert media into formats that your chosen device can understand.
PLAY TO: Windows 7 quite likes multimedia, and its Play To feature enables you to send music to a wide range of devices
Last but not least, Windows 7 gets Windows Touch, which supports iPhone-style multi-touch input (provided, of course, you have the hardware). OS X has touch support via laptop trackpads, of course. Windows Touch could be very important when you're choosing your next PC, but it's irrelevant at the moment for the majority of upgraders.
Everyone's a winner, baby
On the face of it, Apple beats Microsoft in several key areas. The first is price - Snow Leopard is £25, while Windows 7 Home Premium is currently £64.98 at Amazon - and the second is ease of installation: while Windows 7 supports in-place upgrades that keep your files intact, XP users will need to do a clean install, as will anybody upgrading from a 32-bit Vista installation to a 64-bit Windows 7 one.
Snow Leopard is designed to be an in-place upgrade, and there's no version confusion either: Apple sells one version to Microsoft's three retail editions.
Microsoft could certainly learn some lessons from Apple in these areas - although Apple isn't entirely angelic, as Tiger users can only get Snow Leopard if they also buy iLife and iWork in the £129 Mac Box Set.
At least, that's the official story. According to Walt Mossberg of the Wall Street Journal, "Apple concedes that the $29 (£25 in the UK) Snow Leopard upgrade will work properly on these Tiger-equipped Macs." We'll let you know what Apple says about that one.
Overall, though, it's impossible to say whether one operating system is better than another - we're comparing apples and oranges here, no pun intended. As most of its key changes are under the hood Snow Leopard feels more like a service pack than a new OS, and it'll be a while before its biggest changes - such as the new toys for software developers to play with - become obvious to the average punter.
The price reflects that, and there's enough tweakery and polish to ensure that no Intel Mac owner is going to regret spending their twenty-five quid.
Windows 7 is a different beast, with some dramatic differences to Windows Vista. In many respects it feels like the operating system Vista promised to be, but there's enough innovation here to make it more than just Windows Vista Fixed Edition. As with Snow Leopard, you're not going to regret purchasing it - especially if you pre-order it right now before the prices go up on 1 September.
So which is better? We think that's the wrong question. Snow Leopard is better than Leopard, and Windows 7 is better than Windows Vista. If you aren't planning to buy a new computer in the not too distant future, that's all that matters: whichever platform you're currently running, upgrading is well worth the money.