I don't know if this will add anything, or if everyone will just tell me I am full of crap again. But this is my experiences:
I use a PC (Dell) at the store, partly for cost, and partly because I wasn't aware there was a Mac version of the inventory software available. But mostly it was cost. At home, I use a Mac. I do this because I am more comfortable with the system. I just am. This could easily be because it is the system I have used the most, so naturally this is subjective.
In my work experience, I have worked for 3 catalog companies. In each one, the departments that put together used Macs, as did the photo studios they worked with (4 in total). All three had very different method of production, but they were using Macs. I don't know why, since everyone has been saying that they can do everything on a PC that can be done on a Mac. Maybe artists are just stuck in their ways.
Now in addition to the store I sort of have a side business where I help people in Philly with their computers. This is nothing hardcore or IT related in any way because I am essentially working with people who are friends of, or friends of friends of, or friends of friends of friends of my parents. These are not young people. The median age is about 70+.
Many of them are computer luddites. Some are not, such as my dad who took to computers and CAD work with ease (I joke that Dad was a computer nerd who had to wait for the technology to be developed). But many of them had trouble getting the clock on their VCR to stop blinking "12:00". Very often what I am doing is helping them set up the computer for the first time or doing some kind of fix for a problem that cropped up (it is usually not the computer's fault, such as Verizon denying the use of a STMP port and messing up emails all around town). I am dealing with a mix of PCs and Macs, very often these folk's first computer.
Now make of this what you will (and it could mean nothing) but I have noticed that the ones who got Macs seem to *do* more with their computers than those with the PCs. The PCs are often just filling in the position that one of those old email machines could have done - with perhaps a word processor added on. I was amazed when I explained to one person with a lovely looking brand-new Dell laptop that they could use the browser for more than just going to look at their stocks. Wheras another woman who had a Mac, and I thought would never use their computer except to print out medieval paintings (to do so I had to explain the browser and google to her) and maybe email has found all sorts of things to do online, such as downloading German radio programs and other things that interest her. This is typical across my 'customer base' with only a few exceptions.
Mind you, pandering to elderly folks isn't going to be a winning business plan in the computer world, but I do put it out there because when several very highly skilled and knowledgeable computer folks start arguing stats and whatnot and assume what they think is best is what average folks want they might be missing something rather crucial.
Why? According to you they are the same.