Rotella T6; (A Non A40-spec oil) honest opinion?

[Racer Boy]

I use the DT40 in my '02 2.7. It hasn't had an engine failure yet, so how is that for anecdotal evidence?

The car is used for street driving and track days, and the car has 154,000 miles. I've used the DT40 for the last 4,000 miles, so the car (as far as I know) hasn't always used that oil..

[78F350]

I've used Rotella T6 in most of my cars - 986s, Cayennes, some VWs, and a Honda. I am not religious about oil and will occasionally use Mobil or Castrol if it's priced similarly. Before going to the T6, I read a lot on 'Bob is the oil guy' and various forums and concluded what JFP said.
Oil changes look fine and no catastrophic failures ...yet.