I'll try to common sense answer some of the questions, but I am not a oil expert just my experiences
One , oil pressure will increase with a thicker oil, , basically to make it simple the first number say in 5w-30, the 5 is what weight the oil will be at freezing, the second is at operating temp.
As far as different oils , you have mobil, redline, lucas, royal purple, and some others such as shafer.
Your more expensive oils, or specialty oils such as royal purple and redline and so on, have different properties to give higher performance, and better protection properties than the "off the shelf" oils such as mobil. Not taking anything from mobil , for the street it is the best buy for the $.
Do they make a difference?
Yes and no, most of my experience comes from bikes, I have seen 2-7 rwhp from switching from mobil to redline, and get the same protection. But will our trucks get a similar outcome? I really dont know.
The article in Super Chevy? Do I trust it? probably not. Most articles are bought from a manufacturer sometimes and are a little biased.
What I can say is on my duc I raced , which was stroked to a 1026 from a 998 , I ran redline, punished the bike, and at sometimes going in to redline because of gearing issues and never had an oil related problem, and when it was time for rebuild the bearings looked like new.
Honestly on the engine oil side I think we are fine with mobil, the thinner oils give more hp, but a tad thicker gives better protection , especially with forced induction. I think even DC uses 15/40 ro so in there sc'rs.
But I do like there tranny oil and rear axle oil. Even FSTJACK in his SC'd expedition ran redline in the auto, and it made it 126,000 miles, with jack drivin the piss out of it
But make your own choice guys, all is good, its just a matter of personal preference.
But I will say I noticed a huge difference swapping my manual tranny fluid to D4 auto redline fluid, It shifted better and was alot quieter
