Like a few of the others familiar with system building here, I have noticed some serious generalities and misconceptions. At any given point in time, there is going to be one manufacturer (Intel or AMD) that is going to have a higher performance level. But, it is not a constant. There have been times in my career that AMD was slightly ahead and there are others that Intel has been ahead. One generality that does seem to hold true is that AMD is usually less expensive. Does that make it a better deal for a designer? SOMETIMES. It depends on what you expect out of your system, what your budget is, and where manufactures sit in terms of release of new technology.
Personally, since the release of the "Nehalem" series a couple years ago, I have had a very difficult time considering anything other than Intel (especially now that Sandy Bridge has been revised). Yes, I do pay a couple hundred dollars more for Intel, but for me it is worth it. For a system that you are probably going to keep for at least 3 years, that couple hundred dollars breaks down to a few dollars every month and pennies a day. The time I can save with that extra performance will easily pay for itself.
I can honestly say that we test system after system on multiple architectures and you can tell from the computers we sell that I have been very impressed with Intel in the most design software. I test more systems in design software that probably anyone that I know. Even the performance techs over at Adobe are familiar with what we do and sell and can even tell when one of their customers is using a SignBurst. With that in mind, if you are doing some CPU crunching design work, you might consider that.
Only time will tell, but there is sure to be a change in the tides eventually and my current opinions will change. But for now, I am sticking with Intel until the numbers prove otherwise. You may see benchmarks on CPUs here and there, but those are just guidelines. To be sure about what you are testing, you have to test in real-word applications on the exact same hardware as you are going to be using. From experience, I can tell you that benchmarks in other software don’t necessarily parallel benchmarks in design software.
Is AMD more prone to overheating and failure? Again, that depends. Overall, I have experienced a higher ratio of AMD failures vs. Intel, but if you take the proper precautions, AMD processors can be very reliable. Keeping them cool is a big part of the solution. But then again, if you have to pay $50+ for a CPU cooler, you are chipping away at the cost advantage of AMD. Along those same lines, proper system building, cable management, and system airflow can affect the temperatures of every chip on the board. There are so many variables here that it is almost impossible to label one “better” than the other for everyone.
As I have seen soooo many times on this forum, “leave it to the experts”. I would no more expect a sign shop owner to be able to keep up with all the variables in computer hardware than I would a real-estate agent consider themselves experts in graphic design. Yes, that real-estate agent might be able to throw something together, but is it in his best interests to do so? You guys (and gals) would be able to answer that question better than I would.