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The only problem with Apple is that most of the software I need won't run on it.
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What I have found over the past 8 years, after switching from Windows to Mac, back to Windows, then back to Mac, and existing in an office enviornment that (with the exception of my laptop) is 100% Windows is that there is usually a cross platform equivalent program that will work with Mac. I can access our office IBM AS/400, I can run our purchasing software, all the of Microsoft "Office" programs are seamless when sharing files between Windows and Mac. Graphic arts programs and publishing programs are also, for the most part seamless in being cross platform. Now I will grant you that there are specific programs that are not cross platform. There are also specific programs that are not avaiable for the Mac, but with about a quarter million different titles of software available, I've not found any real stumbling block in the business world. MOST things are available or have an equivalent. My wife is a teacher, she also has a Mac laptop, her school is 100% Windows. She has no problems sharing files with the other teachers, students, etc.
I'm not saying it is the best answer for anyone, but it was a great answer for me. I also explored UNIX and LINUX and think those OS's have some real possibilities. They are generally considered more secure, more stable, but they are also harder to get software for. Mac's operating system uses a UNIX core, it gets the upside of UNIX with the software support of Apple.