That's not quite true. Actually you will get more engine wear using synthetic oil with an extended oil change interval than using regular oil with normal oil change intervals. The main factor in minimizing engine wear is the oil change interval itself, not the quality of oil. It's a great myth that because synthetic oil is so much better than regular oil, you can safely extend your oil change interval. Not true. That being said, in most cases you can probably double your oil change interval if you use synthetic oil, but anymore than that you are taking your chances. Also, regardless whether you use synthetic or regular oil, the oil filter itself should be changed at the normal oil change interval.
Your right, but it is partially true as you mentioned in your first sentence.
For maximum life on regular oil, you can drive say 5K. For maximum life on synthetic oil you can go say 15K. Changing either oil out sooner will increase engine life, and leaving the oil in to it's maximum useful life will wear an engine just the same irregardless of the type. However, synthetic base stocks reduce friction, dissipate heat a bit better and less friction means more HP. No, you won't feel the power, but you'll notice better mileage, smoother cold starts and frankly, starting an engine, any engine, is the worst thing you can do to it. By getting a better oil to critical engine components faster, means longer engine life in the long run.
The two oils are completely different, and for people who are unsure about running synthetic oil, most manufacturers have a 'blended oil' which is 50% synthetic and 50% regular oil. I would bet that these guys wouldn't advertise it as a blended oil, they'll tell their friends that they're running synthetic, when in fact it's not all synthetic, only 50%.
If synthetics aren't the real deal, then feel free to phone the guys at McLaren, Ferrari, Porsche, GM Performance, Mercedes Benz, BMW and other premium makes that have realized how good synthetics are, to offer it direct from the factory. As engine tolerances get tighter, synthetics are the only way to go not for a longer lasting engine, but for resale value as well.
If I bought a vehicle with 200K at a very good price and found that the owner was changing the oil with standard oil every 5K, I'd walk away. If he was using synthetic for 8-10K changes, I'd buy it as there would be a lot less possibility of sludge formation in the engine.
I have three vehicles, and two (Durango R/T, '06 Pontiac G6 GT) are running Amsoil 0W30 25K mile rated oil. My '99 Taurus doesn't see as many miles so I run Amsoil 5W20 Xl (7500 mile change interval). All Amsoil filters are good for up to 25K or one year. Yes, I properly flushed my engines and on my Dodge replaced the valve cover gaskets just to verify that there was no sludge accumulation before use. If any problems arise, Amsoil has a warranty where they'll pay for the repair if it was found to be a fault of the oil. Mobil1 doesn't offer that, nor does anyone else for that matter.
Ultimately it comes down to personal preference. A lot of people are scared to do a 10K oil change, or even a 15K oil change. I don't doubt them as I used to believe that was absurd as well. I'm on my seventh year now with my vehicles on yearly oil changes and I've never had one problem. After replacing a leaky oil pan gasket on my Taurus, the engine internals look like it just came from the factory.
Another bonus, is that I save close to $400 a year on additional oil changes and my Dodge no longer burns a quart of oil every 3K like it did when I ran it on standard oil.