The GUI of a Mac isn't that bad. I like it, though it'll take me sometime getting used to since I rarely used Macs in the past, just in school. My sister wants to get a Mac because it would be perfect for the course she is taking (interior design).
I don't think Macs are any worse than PCs or vice versa. Depends on your preference. Really, the only downside to Macs I can really see is the price. Macs tend to be more expensive than PCs, but this depends on what PC you get. My sister wanted to know what laptop she could get that's just as good as a Mac for interior design and it ended up costing her roughly the same as it would have cost her if she got the iMac instead. There are cheaper PCs that are indeed more affordable than Macs, but they may not always come with the best hardware.
There are some misconceptions about Macs that I sometimes still here, one of the most persistent being that "Macs never get viruses". This is untrue. Macs are just as vulnerable to viruses as PCs. The thing is most viruses are written for PCs since they are more popular than Macs. Linux, on the other hand, is, as I said, nearly immune. I say nearly because it's still possible to get infected. The reason it's harder to infect Linux is because the user is, essentially, on a limited account. A virus can only do damage if it's run from Root. Of course you can replicate this sense of security on Windows using a limited account, I believe.
