Fixing the bugs
SP2 also fixes some particularly annoying bugs, including slow shutdowns and tablet users will now be able to see the on-screen keyboard properly at all DPI settings.
SIDEBAR MEMORY: The sidebar still takes a surprising amount of memory for what it does, but rather less than in SP1
The gadget sidebar takes less memory – about 1MB less on most systems – and Microsoft claims the RSS sidebar gadget, which has been particularly prone to crashing, is more reliable.
RSS GADGET: The RSS sidebar gadget no longer hangs every time you click through for another page of headlines, making it finally usable
There are other performance improvements in SP2; DirectX has better 3D performance so you should see slightly higher frame rates. If applications need their own version of a file, these side-by-side (SxS) files should now load as fast as the main version listed in the registry.
Media Center performance is generally better and IE is more reliable when playing embedded videos.
MEDIA CENTER: Playback is more responsive in SP2
If you have Gigabit Ethernet, copying files to and from a network share will be faster because SP2 uses the full network bandwidth.
Moving files on the same USB or FireWire drive is practically instantaneous (and Microsoft claims that you'll have fewer problems with external drives connected when you sleep or hibernate). Vista doesn't always see SD cards inside Windows Mobile phones, especially the T-Mobile Dash; that's now fixed.
FASTER TRANSFERS: Moving files from one folder to another on an external drive is so fast you hardly notice you're doing it; a big improvement
Not many devices use the new SDXC (eXtended Capacity) memory card specification yet but Microsoft added support for the exFAT file system it's based on in Vista SP1; SP2 adds UTC timestamps so files synchronize correctly across timezones.
There aren't enough changes in SP2 to cause application compatibility issues. In fact Microsoft has worked on the Windows Filtering Platform to let more third-party security software work with Windows components. In particular Spysweeper and ZoneAlarm now work with POP3 email accounts.
SECURITY INTEGRATION: It's easier for security software to work with Windows components in SP2; ZoneAlarm now works correctly with POP3 email
Power management is better in SP2; you may not see the full 10 per cent improvement Microsoft claims on all systems but one laptop we tested got nearly an extra half hour of battery life.
POWER EFFICIENT: Improved power efficiency promises extra battery life; systems vary but this Lenovo went from under three hours with a 3G dongle connected to three and a half hours
That could be the best reason to update, but unless you're in a hurry for Blu-Ray and Bluetooth 2.1 these are welcome rather than urgent improvements.