First, glad to see we are headed into some substanative discussion here. Second, the above is exactly the opposite of the opinion of our IT guys. They say, look at the difference, the PC's rarely if ever give us trouble. Or you don't see these problems with the PC's do you?!
With regards to extra staff, by virture of the fact that you have two operating systems under the same roof, you have more invested in tech time to service them. That is irrefutable.
And even if as is your view that the Macs are less intensive to maintain, the question remains, which way is the most practicle to go: all Macs or all PC's?
There is absolutely no way the Macs are going to be eliminated in the company. In fact, the PC's replaced the Macs in many departments and it was a big decision at the time. But none has looked back and said that editorial or accounting or sales or the presses should go back to running on Macs.
So we are left with only one more question: Are the Macs and the associated extra IT costs necessary? I say that even if they have some benefit as you say, the benefit does not outweigh the added expense, not when a PC will do the job sufficiently well enough.
I will give you the point that Macs are better for the sake of making mine. So please explain how Macs are so much better as to justify the added expense (and at our operation, added aggrevation).
Staying in the Newspaper industry, not too long ago I posted an article about a major newspaper where their networked PCs were all infected with one of the 100,000 or so viruses and crashed... totally. There Macintoshes, on the same network, were unaffected. They were able to publish for the four days it took to rebuild everything they lost in the PCs... solely because of the Macs.
With regards to extra staff, by virtue of the fact that you have two operating systems under the same roof, you have more invested in tech time to service them. That is irrefutable.
I disagree with your assertion that having two in house Operating systems has to be more expensive. In fact, I am going to refute your "irrefutable assertion" . . .from the real world.
A business that had around 400 PCs installed had an IT staff of 18 to maintain them (This comports well with the industry standard of one IT tech to keep 20 - 25 PCs working). Under the urging of one of the IT techs, in one department they replaced 40 of the PCs with Macs... and after a few months, they laid off three IT techs. The 40 Macs were easily maintained by one IT guy... the tech who suggested the change. They later replaced 30 more PCs with Macs and laid off four more PC IT guys... and didn't need to hire another Mac tech, because he was still idle 50% of the time.
Last I heard, they were up to around 120 Macs or so and down to about 280 PCs... but their IT department was only 12 IT guys... 11 PC guys and one Mac guy... but the Mac guy is starting to think they might need someone else familiar with the Mac: he wants to take a vacation...
Before bringing in the Macs, their IT department, ignoring hardware purchases, software licensing, etc., and concentrating only on Human Resources, cost about $630,000 a year (18 techs times $35k salary and benefits [est.]). That calculates to about $1575 per PC per year. After bringing in the Macs, it was $420,000 per year (12 techs X $35k salary and benefits)... which works out to only $1050 per computer per year. But if you break it out by OS, it is $1375 per PC per year but only about $300 per Mac per year... and the PC guys are overworked with each of them servicing 25 or 26 computers. The Mac guy is cruising - servicing 120 Macs - when they need it.
Meanwhile, the bottom line of the business was increased by a mere $210,000. Not too shabby.
Going the other way, a local college once had the largest Mac network in the world... something like 3500 Macs on Ethernet. The IT department head retired and they hired a PC type guy... who proceeded to replace the Macs with PCs... and increased his department payroll by almost tenfold... and of course he needed a raise because he was now supervising ten times the number of people it had taken to maintain the Mac network. Of course, the IT manager laid off all the Mac techs... so it will be very expensive and difficult to go back.
Costs were up, individual computers were routinely infected with viruses, Trojans, worms, etc., network downtime increased as well... but the IT manager got his promotion and raise... after all, he was now the supervisor of a VERY large department.
People who worked at the college told me that before, with Macs, if they put in a call for help with a problem that wasn't solved merely by restarting their Mac, someone from the computer department would call them on the phone and say "Do this, click that, and restart... " and the problem would be solved... now, with PCs it ALWAYS requires a tech to visit... who often took their computer away... and when it came back it was ALWAYS missing personalized settings and local files... like email and even LAN email accounts... which would require another call to the IT department to have them come back and reconfigure
Oh, incidentally, this switch at the college was pre-OS X.
It was good for me and a couple of my clients 'cause I got to buy a lot of Macs at bargain basement prices. You should have seen the college staff grabbing Macs at the auction... and heard them bitching about having to use the new Dell PCs and the problems they were having networking them...