I think it is a safe bet that even if anyone knows the answer, he or she will not be able to commit to answering in a public forum.
With regards to maximizing a Mac, it is also a safe bet that Apple's products will get a leg up on anything that their competitors come up with.
If you really like the Mac and want a software solution that harnesses as much of the machine's architecture then it's quite difficult to choose anything other than what Apple churns out on the software side. If you want the best combination of hardware AND software then you will open up your options.
I'm seriously thinking of jumping onto the Mac bandwagon and using their software solutions. The local industry where I am situated at has a preference FCP. AE seems to have a leg up on Motion due to a lack of experienced personnel using Motion. However, I'm quite confident that I will be able to leverage what Motion has to and will continue to offer for broadcast design.
For now, keep your money close to you and make your decision at an opportune time. A decision that is based on industry demands and your skillset instead of putting faith into chips and wanting to be loyal to a company or software.
At the end of the day, most companies won't give a diddly about you or what you have done for yourself or for themselves unless they want to. It is best that you think about yourself and your earning capacity - again based on industry demands and your current and expected future skills.
Cheers
RoRK
broadcastGEMs - AEPro Volume 02 (Professional Adobe After Effects Project Files - Now Available).
Adobe After Effects Training in South East Asia.