The thing with using synthetics in higher milage cars is that they usually develop oil leaks right after. The synthetic particles are smaller and when put into a well worn engine, leaks develop.
If you want to go sythetic, you really need to do it when the car is new or under 5000 miles. When i build a motor i usually break it in for 3000 miles on conventional oil and then switch to synthetic. On all my higher milage motors (that i got later on) i run pure conventional oil.
I see no difference in all in wear. I just tore down a 175,000 mile Ford 5.0L V8 that was run on conventional all it's life and it had very minimal wear.
I think the frequency of oil changes has more to do with it. Castrol is a very good oil. It's also my oil of choice due to it's petroleum source coming from PA. PA oils tend to have better lubricating qualities that TX oils. Another good brand of oil is Kendal. You don't want to change oil brands every oil change depending on what's on sale. Use the same brand and weight of oil for the car's life. If you have oil pressure problems or loose tolerances due to wear, then you can use a thicker oil.
Just keep running the same Castrol 10W30 and perform frequent oil changes and you should be fine.
Oh yeah, NEVER use Fram Oil filters. They are absolute garbage. I would post the proof but it would take too long. Just take my word for it, stay away from FRAM!
PS. My primary hobby is building, showing and racing Ford Mustangs. You are right about newer cars becoming more computer orientated. I have a carbed '85 GT that i can tune with a screwdriver, but several of my newer Mustangs require me to use a special software i installed on my PDA to change fuel and timing curves and other variables. It's gets stressful sometimes but that's what the planted tank is for