I switched from a PC to an iMac over three years ago.
It's the best thing I did in regard to a computer.
No more reformatting my hard drive, no viruses, no third party problems with soft ware etc.
Like Diki, I have not had an anti virus program and don't seem to need one.
I'll never go back to a PC on a permanent basis.
You do really get what you pay for.