I just switched (last week) to the Motul based on the forum feedback. I should have some results to share in summer months.

 

I am trying to figure out what are criteria for choosing the oil for this engine? Why Ford's specs?
Hate to brag about Mercedes experience, but MB has their site, listing oils very carefully and their best class for oils working with DPF is 229.52
I've been using

Motul 109471 8100 X-Clean EFE 5W30

who meets that classification and was always getting good tests results.
Other is

Valvoline European Vehicle Full Synthetic XL-III SAE 5W-30

who often is on sale and cheaper, than Motul to start with.
In older diesels I was using Rotella T6, but this is not approved for use with DPF.

 

No worries, you're not the first fanboy we've come across.

The Tdv6 is fairly close to Powerstroke 3.0, hence the ford spec.
You can also use JLR spec STJLR.03.5005.
Based on the UOAs and general feedback from the community here, this motor is more sensitive to oil change intervals (instead of a particular brand of oil).
So, we typically stay away from extended intervals, unless you have extenuating financial circumstances.

Ultimately, it is your choice; do what makes sense to you.