I am probably one of the few here who uses Rotella T6 5W-40 in my specific application. I also probably make some cringe on here.
It is used in my 2009 Accord with a 4cyl. I used to consume approximately a quart of oil every 1,500 miles. With the T6, use a quart every 4,000 miles. Big improvement IMO. The K24 in my Accord now does fall under a warranty extension, and can be tested (measuring oil levels) to see if it qualifies for new pistons and rings, but it runs way too sweet for me to want someone to tear into it. For now I'll live with T6 and some consumption.
The T6 has had no ill effects and IMO the engine is smoother when blasted up to it's 7k redline, that of which the car is no stranger to under some more than spirited driving.
I absolutely love it.