A Mac is fast indeed, but I build myself a computer last month with a Core i5 Sandy bridge, 8gb of 1600 DDR3 ram and 120 GB SSD (Solid State Drive).
I can assure you, it's fast
Some examples of booting times:
PS CS5 64bit: 1.25 seconds.
Windows 7 Pro 64 bit: 12 seconds.
The booting times is not what interests me too much, it's the responsetime with video-editing, rendering, copying of large files, etc.
A few years ago MAC would be the better choice overall, but nowadays I don't see much difference anymore for a homeuser if you have a self customised desktop.
Note: I'm talking about self build systems with the right components, not about manufactured computers from brands like Dell, HP, Acer, and so on.
When it comes to design and visual, mac is still the best choice. It's elegance hasn't been beaten by any all-in-one desktop.
Although, I like my PC just fine the way it is now