Prepared for Your Pithy Rejoinders and To Be Ignored...
Perhaps it has not registered with you that Philip has a nice side line upgrading / customising Mac mini's and selling those on eBay. As such it means that he has lots of interest to make sure that what he sells will work without the stuff coming back to him. If memory serves right he has sold 450 plus Mac mini's.
I am running the machine for a business and downtime / hickups can cost me dearly, far more than that any PC or Mac available is costing. I am fond of how compact and portable the Mc mini is, in addition it does not get easily damaged by being squashed in the overhead lockers in the planes (unlike laptops).
This means that I take note of what Philip's experience is which collaborates with my own.
I know about his little eBay biz and his occasional unsubtle references to it in his posts that can cross the line regarding this forum's rule against advertising and self-promotion.
And like you I depend on my Mac to make a living, which is why I always have at least two Macs as well as the usual redundant on and off-site backups Just In Case. Even Macs that are perfectly functional when new can die at any moment with little or no warning...
All I am saying is that Phillip and others like him seem to miss the point: Macs are mass-produced electronic devices that are vulnerable to myriad calamities during design, production, shipment and use. They are intended to be used for creativity and the appreciation of creations: they are tools as well as entertainment centers.
But in the minds of some people they are akin to fetishes, things to be coveted, even worshipped. They must be cosmetically perfect with hardware to match. Slight differences in specifications and performance are the subject of endless obsessive debate. It all becomes rather tiresome after a while...
A Mac is merely a consumer product that comes with a decent warranty should reality rear its ugly little head and the object of desire suffer a premature end. So It Goes... If it is purchased from Apple the 14-day return period is ample time to put it through its paces actually using it for its intended purposes; some retailers have similar generous return policies.
If you want to run RAM tests for hours on end and torture your Mac until it runs as hot as a toaster, obviously it is your choice. If your computer needs actually require flawless performance while maxing-out a CPU 24/7 for months on end without the possibility of failure (everyone who has those real-world requirements please hold up their hands ...) then I suggest that you have multiple Macs on hand because such an animal does not exist. Otherwise millions are sold and used every day for years before they need to be repaired or replaced. Buy extended AppleCare (I recommend the L.A. Computer Co. for its consistently low-prices) if you want long-term peace of mind.
I am addressing those who are not inclined to indulge in Mac veneration but who might get sucked-in by accident as they peruse this forum: Enjoy your Mac. Edit your images with Photoshop. Get Handbrake up and running and then read a good book while it grinds away. Make love to your Significant Other while your fave tunes emanate from your iTunes library. Just don't waste your precious time worrying about stuff that doesn't make a difference to most of us.