I would recommend sticking with the PC version of Quicken since it is far superior to the Mac version. Instead of buying the Mac version buy Parallels Desktop and install Windows and PC Quicken. If you already have an XP disk this route will not cost any more and provides greater satisfaction. At least in my opinion.
I am by no means a power QB users but I have moved my files over to the Mac. My Mac came with a free full version of QB 2006 for Mac (not the PRO version) and I ported all of my files over. One note of caution, if you will be exchanging files with accountants and the such, they will need QB 2006 for PC or Mac in order for the sharing to work. QB Mac 2006 to anything else prior will NOT work.
I had been very reluctant to move from Quicken PC to Mac, but did it about a week ago. Not that difficult, other than you'll have to re-enter online payees and scheduled transactions, and maybe a few other things. It did not lose data, though, and the Mac version works fine. No regrets.
The PC and Mac versions do not use the same file structure, nor are they feature compatible. I've been using Quicken for more than 12 years (all on a PC). I wouldn't even consider the Mac version. This is why Parallels exists. Parallels lets me run the PC version of Quicken and preserve everything I've spent so long and hard accumulating. I don't ever see convergence between the Mac and the PC version (the Mac version was a complete afterthought) and so I'm happy I have Parallels to solve my problem. The good news is that Turbo Tax for Mac is identical to TT for the PC so files can move back and forth with impunity.
My advice is to stay away from Mac Quicken unless you're just starting, or only have a few years' of data. Anything else and you're asking for disaster. JMHO.
Let me echo the earlier comment -- stick with Quicken Windows via Parallels. I tried to move, but it just wasn't working out. But Parallels and Quicken have been great.
Read CAREFULLY the info from Intuit. Much info and transactions especially securities do not transfer over. You'd think a QIF is a QIF, not so. I gave up thinking about the move and use Parallels with Quicken for Windows. I cannot lose 14 years of data.