Passat TDI: Solenoid injectors vs. Piezo in the Jetta. AdBlue exhaust treatment in the Passat TDI (unrelated to HPFP). Both cars still have diesel particulate filters. Fuel routing through the filter is different.
AFAIK, the HPFP fuel pump is identical in design to the 09>>>, however, VW has "updated" the original pump with several subsequent versions...still, the same basic design, though.
There was discussion elsewhere on this site (more searching for you, I'm afriad!) that the updated versions possibly have different coatings, or even changes to the metallurgy used. I read a bunch here, and I never read any conclusive information what the changes are, only speculation.
You are correct that the failure potential still exists. The disaster isn't the failure of the HPFP itself (failures will always occur, over time), but rather that the failure damages the entire fuel system. There still isn't any sort of containment that has been designed/engineered, although member Eddif has a thread that is aggressively discussing post HPFP filtration.
I will state, though, that the frequency of HPFP failures, at least reported here, has dropped dramatically, even as accumulated miles have increased. You can read into that whatever you want.
You're not alone with these questions. Plenty to read here. Your potential purchase will depend on your own interpretation of these posts. I'm afraid, though, you will NOT find definitive answers to your questions.
Seriously, noone knows at this point, I haven't heard about any failures to date which is good but, it is too early to really know how things are going to work out.
