On OS X vs Windows, there are differences but nothing that the everyday user needs to be worried about. There is a slight learning curve but you get over it in a few weeks of use at most. Some of the main OS X differences are that you don't have a start menu, the menu bar for a program is fixed at the top of the screen vs being attached to the window, there is no My Documents (you use the Finder), you close a window by clicking the X in the upper left corner of the screen vs the upper right, & closing all of the windows doesn't necessarily quit the program. The Mac is much more of a drag & drop interface. Nothing major, you just need to get used to it.
For drawbacks, one of the big ones is that if you have a program that you use on Windows that isn't available on the Mac or you have program that you don't want to buy again to get the Mac version (maybe like Photoshop). Now that you can install Windows on the Intel Macs, that's not an issue. You can either use Apple's Boot Camp, where you get a menu to pick Windows or Mac when you turn the machine on, or by using
Parallels or by
VMware Fusion to do it from the Mac desktop. In all of these options, you do need to buy a full retail version of Windows.
Other drawbacks are that some programs just lag behind in development for the Mac. They make it but it might be 3-6 months later. Photoshop Elements is a great example. Version 6.0 just came out for the Mac. They completely skipped version 5.0 & never shipped it. Not to worry, we are seeing resurgence of very good image editing programs like
Pixelmator which is cheaper & very impressive for a version 1.0 program. Some other examples are Netflix allows streaming of movies to your computer (in the U.S.) but their Mac client is still in development & some financial institutions use Windows only based software to authenticate your login. Last one, if you are a hardcore gamer, I would not recommend a Mac. Not because the games don't work, it's because hardcore gamers like to always buy the latest video cards & tweak their systems to death. You are better off on Windows.
Next time you are in your favorite big bookstore, check out
Switching to the Mac: The Missing Manual. This is an excellent series & the Leopard version will be out in a few weeks (until then, check out the Tiger version). Skim through the first few chapters as they hit the main differences. Then, use it as a reference book & read up on things as you need to. A couple quick websites to check out are the
Apple switcher site,
Switching to a Mac, & here is an article from
USAToday on switching. Apple just launched
this site with has some nice videos on it. Check out the
Move to Mac video.
Lastly, if you do make the jump, drop me a PM & I can send you more detailed instructions on how to move your Firefox & Thunderbird profiles over & also get you a list of my favorite Mac utilities & programs that will make your transition a little smoother. Also, if you have any more specific questions, feel free to ask.