With certain minor conditions and restrictions applied, I think that the thin issue is way over blown. There are all kinds of applications that take whatever oil you're spec'd for and subject it to "stresses" that can effect its operational viscosity. The service rarely results in elevated wear beyond the added power output applied in the service. A SBC towing with spec'd 5w-30 may have slightly elevated wear profile ..but it more aligns with the added power output than it does the reduced viscosity due to higher oil temps. Now, typically, the service shortens the life of the oil ...but in general ..I don't see anything that the oil is contributing to the wear. Remember, conditions and restrictions apply. It assumes no abnormal influences like fuel issues and whatnot ...but those effect all oils of all viscosities and may produce elevated wear regardless of if the viscosity drifts or not. That is, even if you have fuel dilution that effects viscosity ...there's a false assumption that the lowering of viscosity is the cause of the elevated wear. Terry can teach you that if you hang with him a bit.
As was mentioned, anyone in typical service rarely sees full operating temp. Although we may have done ourselves and know of people that commute mega distances, most are within a 20 minute (or less) window of operation. This is the main thrust of the move toward lighter oils, imho. We make the false assumption that this is going to have a downside to those who operate at the steady state to a larger degree, but I suspect in reality it's merely to take advantage of one more window of opportunity to scavenge "more" from the normal operational cycle of all engines. Just a corner that they never swept out until recently. They found it had more to offer than they thought.
(forgive the sideline hijack)
btw- my bruceblend® is going to be tested shortly. My delays have all been due to tweaking of the various ancillary components in the heating/cooling (it has been somewhat frustrating). I fear that they're going to introduce "new metals" into the mix that are going to skew the results (my cooler is copper/etc)..let alone break-in materials/residuals. This is exclusive of a 15 year old injection system and the potential issues there let alone any unknown effects of a additive package that makes Redline look like SM. Observations have produced no downside to this thin oil. No consumption ..no hot idle HLA noise (intermittent 220F temps) ...nothing. Fuel economy appears up notably after, what appears to be, a 3000 mile break-in threshold. I hope to do some long trip type of testing to see if I can top previous economy highs (24.X). As it sits right now, I can achieve 20+ mpg in mostly short(er) trip service where this would normally result in 15-17 mpg results.
After I get what I want out of all this tinkering, I will run this oil nek-kid (no heat exchangers/coolers) to get some cross usable data that may mean something to everyone.
Lou- I highly recommend using Terry to validate the suitability of this oil. I personally see nothing wrong with its use ..and would do it without hesitation ...but I'm the guy who jumps into any unexplored territory with no more than curiosity as my driver and the realization that I'm not going to "destroy" an engine in the time frame of my experiments. If I put 10k of added wear on an engine in 3000 miles (plug in numbers of choice), am I really going to take all that much equity out of the engine before I can turn back to the safety of the kiddie pool?
I think not.