I had the exact same conundrum about three months ago. After TONS of research, I decided to build my own PC and I am extremely happy I did. The CS5.5 Master Collection runs beautifully and I FINALLY have control over my hardware. You can put whatever Quadro card you want, whatever processor, RAM, and the list goes on...
And did I mention that I saved loads of money building it myself?
If you aren't afraid of a little bit if work, you can save a lot of money not having to buy overpriced Apple hardware. Also, with Adobe Cloud, you no longer need to worry about what platform you operate under (Windows 7 is a good operating system).
Just my two cents. I hope it helps!
-Keith (a differnet one)
>whatever Quadro card you want
If you need 10bit output for a special monitor... yes
Otherwise save $$ and have better performance with a GTX card
[Moved to Hardware Forum]
Agreed, if you don't need a Quadro card, save your money as a high-end GTX will outperform most Quadros. Although, 10-bit IPS monitors are awesome.
Keith, take a look at our PPBM5 benchmarks, while we do not have any native Mac data you can see what it takes to make a good system perform well if you carefully analyze the data from over 900 submissions of the test results. Make sure you first filter on either CS5 or on CS5.5 to get fair comparisons