LOL, long story.
For as long as I can remember, as far as engine oil, I used BelRay EXS. I really like the feel of engines with this oil. Problem is that the price has been going up and it got to the point where it got ridiculous and customers started to bit(h. The company also has a bit of an attitude problem.
On my own bike I started to use the Mobil15W50 car oil (mainly to see what if anything happened), and in the customer bikes the Mobil 20W50 motorcycle oil or the RedLine, reason being that if something were to happen due to totally unrelated causes I did not want to hear about it.
Keep in mind we are primarily a machine and engine building shop that does work for other shops as well as a contract R&D shop, and only service bikes as a favour so to speak, customers we have built engines for and their friends, guys we ride with and the ocasional good looking lady. Lately it is getting out of hand, so we may have to cut it down a little, and we don't stock large quantities of parts other then hard engine parts.
Now the Mobil car oil changed so to me it is no longer a option. Since I keep the gearbox and primary RedLine I decided the oil discussions were taking too much time, so I decided just to keep RedLine stuff and if they did not like it they can bring their own. No one has yet.
So, if the question is what I use right now, the answer is RedLine, but it is by no means the only answer, there is more then one way to go.
I usually change the engine and primary oil on the bikes at 5K, but if on a trip I have no reservation running it until I get home.
When they speak of localized high temperatures they are much more specific then "rear cylinder". The top ring on these engines runs real hot, and there are significant advantages to running a good synthetic oil, in particular one with a ester or diester base. This is the reason for choosing RedLine over Mobil, even though I suspect the base oil in the Mobil motorcycle oil is not the same as in the car oil. They call the formula trisynthetic, meaning they use 3 different base oils and this is confirmed in their tech literature. I suspect the percentage of ester base in the Mobil motorcycle oil is higher then in the car oil, I can't prove it but it sure feels like it.
Both the Mobil1 motorcycle oil and the RedLine are very good oils.