WeIl, I recently bought a 280? ASUS netbook. My girlfriend has a MacBook (from the time when Macs were still quite good), so I know both sides.
First, hardware comparison:
Granted, her screen is a lot bigger than that of my netbook (of course, it's a netbook after all), but in summer we regularly sat outside when studying. Well, we tried at least. I could read my screen mostly fine, could see anything I wanted on it. On her screen, she could see... her face, and a portion of sky. I personally like seeing her face, but looking at her doesn't really advance knowledge of electronics.
I often use my netbook in lectures, be it to write stuff down, have a quick look at something on the web, checking mails/calendar... whatever.
It perfectly fits in my bag, hers is quite bulky (again, netbooks were designed to do that, so no problem there).
The battery lasts for about 6 to 7 hours of normal use (not counting prolonged periods of standby, and definitely not counting hibernation), while hers lasts about one and a half, with a (according to the label) higher battery capacity.
Her MacBook has built-in Bluetooth. On the other hand mine has three USB Ports as opposed to two on hers, and I can easily sacrifice one for a 6? miniature bluetooth antenna and still have as many USB ports as her MacBook. Also, she is unable to copy files directly from a USB memory stick or cardreader to her USB harddrive, because the ports are so close together that she can't plug in both at the same time.
Our keyboards are basically the same size, only I have more buttons/commands. For example, she has no proper "del" key, I can switch my WLAN on or off quickly by pressing a command key, she has to use that taskbar thingy. She is constantly annoyed by her touchpad doing stuff when she accidentally touches it while typing, I have a small button right in front of my screen to just disable my touchpad completely if I want to.
Did I mention that my touchpad is also multi-touch capable and actually has two physical buttons, and when I enable tapping I get single-finger tapping for left, two-finger-tapping for right, and three-finger-tapping for middle button instead of using weird hotkey-like combinations.
My netbook has a proper VGA port, something I actually looked out for. When she wanted to attach her MacBook to her TV (which is VGA compatible), she first had to pay Apple another 30? to perform a basic function any other notebook can do straight away. We didn't pay the 30?, but found the same kind of cable with a slightly more pragmatic design (still white, but not polished, and with screws to fix a VGA cable to it) for 8?, which was pretty reasonable.
Well, that's all of the hardware differences that come to my mind right now.
Now, the software (basically MacOS vs. Windows, of course, with matching other software, again, so you might want to skip that):
When I want to launch a program, I tap my touchpad with three fingers (or hold Shift-Ctrl) and draw a symbol on it (for example, an @ for the default mail program, and I can assign letter, simple geometric shapes and numbers to basically as many other programs as I have symbols left) and it starts. For other programs, I can use the new taskbar, or the built-in shortcuts for pinned programs (Win+position of the program), and of course, there's the start menu, and in case I don't want to browse through that I can just type the name.
She has the amazing choice between the Dock and the "applications" folder, or spotlight if necessary.
Speaking of applications:
On Windows, an application usually brings an uninstaller with it, that can be used to remove the application, its registry entries, any context menu items, and if desired also any associated settings files and whatever was stored in user profiles.
On the Mac, you can just delete the application from the applications folder, and be rid of it. Leaving behind everything the program ever put into your user folder, your library and whatever places are available to put stuff in. We tried to uninstall a preloaded virus scanner demo from her Macbook, to install an actually free one. It took us about one hour, and I'm pretty sure there's still something left, but at least the system doesn't try to start the tray icon on boot anymore.
Actually, these problems also happen when uninstalling Apple software from a Windows PC, it'
s really difficult to remove them completely.
Also, most settings are easily available in Windows, on Mac we had to dig through lots of unintuitively-labelled settings just to get her Wireless LAN working properly. Same for printer setup, and basically anything that didn't involve only Apple products.
Mac OS has no proper maintenance tools. Of course "Macs don't need to defragment, they do it automatically". Yes, they do it automatically for files below a certain size (i Think it was 20MB), so if you have a heavily fragmented movie on your harddisk, you can definitely expect playback trouble because of the AMAZINGLY FAST MacBook harddrive, and you can't do anything about it. Also, no defragmentation means no optimization either, so your files are evenly distributed across your harddisk unless you keep care not to fill it up too much.
Also, Mac OS does support FAT32, one of the most fragmentation-prone file systems still in use, and you can do nothing to defragment that.
A real hard disk error scan tool like chkdsk seems to be missing too, at least I couldn't find one. All that seems to be possibly on Mac OS is "repair the permissions". Seriously, how robust can a system be that has to repair file permissions occasionally? And of course, there's also a problem with FAT32 drives. My girlfriend has her USB harddisk running in FAT32 for increased compatibility (or actually, any compatibility at all), and I had to have my computer repair it a few times already, because her housemates regularly managed to blow out a fuse when cooking, cutting power for her room (OK, actually the wiring in that house was crazy too. I can't imagine any good reason to put the kitchen and the other rooms on the same fuse).
Speaking of compatibility: Windows can use any location it can write to as a backup destination. Mac OS requires "Time Machine" compatible drives, so an NAS, to support Mac OS backups, has to create an image with HFS file system, mount that, and make it available on the network, while a simple shared folder is sufficient for Windows (which also uses an image file, but creates it by itself).
When I write stuff to a USB drive, only the files I wanted to copy get transferred there. When she does it, you end up with a bunch of special Mac OS files on the drive as well. This also applies to archives, which can be really annoying. Apparently these files are used to store Mac OS specific data that can't be stored on FAT32, and simply asking the user if they want to copy the files without these filesystem-specific attributes, like in Windows, seems to be too user-friendly.
Also, Windows can seemlessly integrate shared folders and to an extent even FTP and other servers into the interface. On Mac OS, I still haven't found a way to do something similar.
Speaking of network: Windows by default accesses any DLNA-compatible media server on the network. In tzhe case of Windows Media Player even acrosss the internet (as shown in the Win7 ads), iTunes seems to be limited to iTunes-specific servers, as far as I can see, at least I was never able to access a DLNA server using iTunes. And of course, iTunes servers can't be accessed by DLNA devices either, so basically, if you want to watch iTunes stuff on a TV set, you need to buy the also ridiculously overpriced AppleTV, or similarly overpriced adapters for your MacBook.
Also, Microsoft doesn't charge for service packs. As far as I know Apple progressed to OSX SP7 by now...
As for the "stylish and impressive" argument: Some people in our lectures use MacBooks during classes, and concerning computer-related comments, I hear "Hey, you still got battery life left?" or "Cool, you start programs with gestures?" a lot more often than something like "cool, a Mac!". The ASUS is white and shiny too, by the way.
Seriously, the only thing i can recommend about this whole affair is:
Try to talk your school council into thinking rationally.