I'm a Mac convert: the Mac OS has a few irritations, particularly the file structure which took some time to adapt to. But it runs MS office perfectly well; I need this for work use. I have a company Dell laptop running Windows 7 Pro. It works but I use my own Mac when travelling in preference.
I have a Mac Book air, it is light, has long battery life, boots up in secnds and never crashes. Overall it is easy to use.
Yes, they are, compared to a PC, expensive. But look at residual value. A 3 year old Mac Book has real value, a 3 year old Dell or other main brand has little value and a 3 year old store brand laptop has no value.