(This is intended for FixedTouareg, two or three posts above.)
Thanks for your patience :- ) That row of 3 previous posts were a function of being unfamiliar with how this board works. That is, I thought I was replying to specific posts, but was in fact shotgunning the entire board. (Ten years ago I'd have been *terribly* embarrassed; but now? Not so much. I'm an old codger and have earned the *right* to brain f*rts and "senior moments :- )
(I did like your "stages of loss" metaphor, by the way. I think I've achieved "acceptance", but remain just a tad short of "understanding" :- )
As to the second go at a fix (a retry due to the lurching problem) and the fuel filter change-out, so far so good. No lurching or stalls. At cold start, the motor sounds a bit louder than before, but nothing to write home about. Shifting is smooth and consistently within optimum rpm range, except that it seems to want just a bit more - maybe another 200 rpms -between 3rd and 4th.
Some of the "spunk" is gone, sad to say. I'm not a lead foot, but do miss the punch I used to have. There's an expressway entry ramp I routinely use, and with the "pre-fix" Treg I'd typically have to back off a touch at the top of the ramp to match speeds and merge. During four entries over the past few days, it's gone the other way... having to run a quarter the length of the merge lane to finally match speeds. But even so, the cars behind me on the ramp "got small" pretty quickly in my rearview.
Just for chuckles I tried the Sport mode for a while, shifting up at around 3,000-3,500 rpms. I don't use the Sport mode typically, so don't know if it's unusual for a subtle low-pitched whine - or maybe "moan" - to develop above 3,000 rpms, but I'm not going to worry about that unless someone tells me to. She downshifted nicely in Sport mode through a chicane near where I live.
I'm as perplexed as you are about the variety of reported experiences here. My only complaints were the brief (but scary) stalls - three or four instances of that, especially scary when turning left across incoming traffic - and of course the lurching after the first fix effort. They may come back, or they may not, so I can't say (yet) whether the fuel filter change-out has had any effect. But I thank you again for the suggestion. The symptoms were *exactly* as I'd experienced with my Chevy 3500, and I really don't expect a recurrence of the lurching problem.
So if those problems don't come back and all else continues as is, let me sum it up this way:
Back in 2013 I spent 3 months searching the market for a vehicle to replace my diesel truck, and settled on the Touareg for a variety of reasons, none of them having anything to do with running rallies or gymkhanas. The power and smooth operation of the Treg was just a pleasant surprise added on to all the other features that eliminated the competition.
I can comfortably say that if the car continues on as it is now, I'd happily buy it again. Now, let's hope this shows up in its intended place!