More or less, the article tells it like it is. Naturally, I have a few things to add:
With the soundcard in my Mac and Core Audio in OSX, latency is less than 1.5ms. The same card in a Windows XP system can do about 8ms (which is acceptable).
The point about building a PC specifically for music is well made, and it is refreshing to see at least one review where they actually mention that it won't be any cheaper than a Mac system when you're done.
What they didn't mention is that you will find you also have to tune the Windows OS specifically for music production. You won't be able to use it as a multipurpose machine and expect the music side to stay functional.
As far as building the PC goes, you have to pay attention to each hardware detail, right down to the choice of motherboard make & model and processor (hint: everything's gotta be Intel).
If you're interested in using a laptop, you can do it with a Mac (including an iBook) but it's not recommended for PCs. For desktop systems, go with a tower with PCI slots.