1. Sure, but the MBP has the advantage of being truly portable so adding the cost of an external monitor to the equation provides that compensation. With the Imac you're just replacing one screen with another and absorbing the cost of the replaced monitor. There are no advantages to compensate.
2. This is a myth. First, Mac hardware uses the very same CPU, chipsets, memory, etc, etc as a PC. They both 'just work' equally. What gives the Mac an advantage towards having less issues is Mac's are built from a very limited number of components compared to a PC and require less drivers, supposedly allowing more time and validation going to each.; Drivers are built into the Mac OS, but can come from MS or the OEM (or both) with PC's. With PC's you have the choice of thousands of pieces more of hardware. It's wishful thinking to believe they'd be as well validated, in some cases they are but in most not. Personally I think the OEM's put the most resources/effort into drivers for their 'workstation)premium)' lines than for their cut rate bargain lines. As they should. So, what's an advantage to one could be a disadvantage to the other. Either way it's easily something you can choose through a bit of education or even paying attention.
Let's take this a bit further. You say Mac's have a 25% premium. As accurate a number as I could come up with. But it's more about the buyer. What is their motivation? Price, or less problems? I'd say that when given a choice, consumers tend to shop price first. Apple simply doesn't allow this. They tell you what to buy and how much you're going to pay for it. In return they provide you a solid well validated product. But this doesn't mean you couldn't do better with a PC. You can. But to do so requires a bit of knowledge and more.. keeping up with the industry. I can easily build PC's with a higher grade of hardware than Mac's come with. Many of my customers are cost no object buyers, they simply want the best PC money can buy for their needs. Not for someone else's needs. If a certain video card would benefit them more, then they'll buy that video card. If it won't, either because it's not as powerful as another video card, or because their work flow can't make use of the advantages.. then it is not the best buy. For them.
3. Enough for what? I'm not being flippant. I just think there are better ways to match a computer to a user. Most computers sold today will allow the running of CS6 and LR. For some this will be enough. Others will want more storage, or more connectivity, or a better screen, or cooling for a demanding environment, or with a certain look that matches a new desk. PC's allow that customization. Mac's allow 'some' customization, but at a much higher cost. But what really makes a computer suitable for a professional user comes down to time economics.
A $500 machine from Tiger will eventually arrive in one piece. It will run CS6 and LR. Perhaps not very fast, and perhaps it won't store as many images or video footage as they desire.. but it will work. But when you get into productivity time is money. If, at the end of the day, I can finish my work an hour sooner.. if a machine will do that for me.. then it's worth the cost of upgrading. To me. For others 60 minutes extra per day is worth a lot less. So sure, a Imac might process pictures for 85% of the users out there. But does it maximize their own personal economy of time? Probably in less than 10% of the cases. In the rest I could show them how to have just as reliable a machine, or even more reliable. Which fits their needs better, and will allow them to do X amount of work in Y minutes less per day. I can do this because of the vast number of choices available when custom building a machine. And almost always for less cost. The more someone needs in the way of hardware. the more I can improve their economy of time.
To do this effectively I have to know both computers and photography at the customers level. Or at least have resources at their level. And frankly, photographers at this level make more with photography than building PC's. I'm just in a unique place where I have the time. Why some people think some kid making $8 an hour at Best Buy can effectively guide them to an effective purchase is beyond me. But this is where Apple does well. They strive to only sell quality well validated gear.. customers can count on this even if the level of gear is above or below their economy of time. With PC's it's certainly possible to do as well or even better. But it's more easy to do worse
Steve, good and accurate explainations.
A few years ago, the choice would have been clear
In what image work is concerned: Mac.
During many years, Mac has been the no-brainer
Working machine, while peecees were for the
Secretaries and kids gamers. Unless you were runnin
An Autodesk soft under Linux.
But Pcs have changed, so has Mac.
Now the power balance is on the peecee side
And even usability since the windows op aren't
The garbage anymore they used to be.
I don't even run an anti-virus in my PCs anymore
And no prob in years of use.
There is simply too much power and customization
Available today and at lower cost to be ignored.
But as T and you pointed, a peecee needs to be well
Configured.
I beleive that Mac is going to target a mass market
Each time more while the big power for demanding
Tasks is going to be pcs. It's already happening.
In what motion imagery is concerned, Mac is more
A burden now than a racional choice, unless you
Are a fcp user and-ir wants to write prores.
But with DNxHD 444 that's not even as attractive
As it used to be. fcpx aint for the pro crowd anymore
And more generaly, a proprietary system, non cross
Platform in 2013 Seems to me a complete paradox.
We don't need codecs that can be used in a system
Only. When RAWvideo will be the norm soon, the
Need for prores writting will be close to zero. Bye bye
Controvertial and problematic QT container too.
People will work on high-end peecees cheaper in RAW
Video real time, master in JPEG2000, fx in openEXR.
But the Mac design cool factor in an advertising agency
Will remains attractive enough.