[safemode]

mplayer with all the right stuff compiled in can playback _anything_ except the latest versions of maybe quicktime/realplayer or flash. With a good gui, a windows user would never look back. The only drawback is you need a special branch of mplayer to deal with threading, which is kinda required for playback of h264 at HD resolution without hardware acceleration. You may or may not be able to find this branch pre-compiled, it's still very experimental and doesn't like packed b-frames.

[ozda]

As others have said, it depends a lot on your level of comfort with installing and configuring the OS. I can only share my own experiences and opinions.

I bought the first model released in Australia, WinXP black 16GB SSD w/ 1GB RAM. The default XP install performed really badly so I wiped the HDD and installed Ubuntu Hardy, netbook remix and upgraded the RAM to 2GB. I later upgraded Ubuntu to Jaunty and got bored of netbook remix so I now run a regular Linux desktop with an Amiga theme, sweet.

The boot time is approx 20 seconds to the login screen and about 5 seconds from login to desktop.

My Ubuntu uses ext2 file systems and has no swap drive. I tend to have 1GB of free RAM available when running Firefox and OpenOffice. I'm running out of storage atm so an upgrade to a 32GB Runcore is on the cards and I'm anticipating a nice reduction in boot time from that upgrade!

On the mobile Internet access front I run Blueman which allows me to expose my Nokia N95 3G Internet as a network device to Ubuntu. Combined with Network Manager this means that from a cold start I can be on the net within 30 to 40 seconds; startup, login, right-click Blueman icon, connect N95 via bluetooth and the Network Manager auto-connects to the Internet. This is really handy on the train as I don't need to plug my phone into the laptop nor pay for an additional connection or have one of those ugly 3G cards sticking out of the Mini. Blueman is a truly amazing tool.

I use the machine for web browsing and email as well as work related stuff like ssh, RDP, Google Apps. OpenOffice provides me with an MS Office compatible suite so I don't miss Windows much... I do have an 8GB SDHC card which has a Windows XP virtual box and Visual Studio Express on it in case I need to work on C++ and C# projects. Windows XP performance under virtual box and Ubuntu is far in excess of the default XP install I found on the machine when I bought it.

I suspect one can do all of the above with OS X but from my perspective OS X is too much of a learning curve for me (I'm a right clicker) and GNU/Linux is something I know well. Based on my experiences I doubt that Windows XP would give me the smooth experience I'm currently getting. Maybe Windows 7 will come close. I might give it a go when I upgrade the SSD card.

[lunasdude]

As a user os all three systems, I believe (and I'm biased) that the least trouble AFTER install is going to be OS X. Win xp is going to require a LOT of matance, anti virus, spy ware etc.
Linux is fine as long as you are an accomplished user and understand it.
Assuming you know all three systems OS X will give you a sweet ride.
Just my Opinion and you know what they says about those! LOL!