Flew in December SGN-CAN (A320 or A321) and CAN-SFO (77W) in J.
Check-in at SGN was kind of tedious. The agent (I think outsourced by VN or an airport services company) insisted to see my printout of my Visa Waiver Program ESTA receipt (it is electronic so you don't really need to have a printout) and also insisted that I should produce evidence of my accomodation in California and ticket out of the U.S.
I used then my SkyTeam Elite Plus credentials to use the VN lounge and I invited a friend (no SkyTeam status) who was flying VN to SIN around the same time of my flight to CAN. It was a mess. The lounge dragon said I could not bring him in (SkyTeam Elite Plus members may bring guests into a lounge) and blamed CZ's policies for that. We talked on the phone with a CZ agent and after about a heated discussion on the phone, my guest was finally let in. Part of the problem was for sure the VN lounge staff, but CZ made it worse by saying categorically they would not accept me bringing a guest. Fortunately they relented. The wine was hideous at the lounge, but the views of the apron and runway were pretty cool.
The A32X flight to CAN was amazing. J was semi empty and the purser was incredible. She was cute, perfectly groomed and amazingly friendly. The food was okayish. The IFE was in the form of a tablet. I saw a movie that was more or less good... the selection was not that great.
Transit at CAN was fine. I had enough time to explore the CZ lounge and have a drink there. The lounge is big and modern (but in a super strange layout), albeit very crowded and somewhat dark. The food/beverage selection was very poor. The placement of the electric output jacks in the area where I sat was weird also, so my 3-meter long iPhone charger came in very handy. I did not spend much time at the lounge because boarding started very early and CAN is a large airport.
The 77W was in great condition. The seats (1-2-1) are quite nice. If I am not mistaken, they are the same seats that GA uses on their 77Ws. My seat was a window seat but I stupidly selected a seat that was not right next to the window, but that was right next to the aisle. Dunno if that makes sense. Take a look at Seatguru.com to see what I mean. Service was good but not as good as the narrowbody experience. The champagne was fine but the flight attendants were not proactive at all in offering top ups. Dinner and breakfast were meh. IFE was pretty good and I was able to sleep very nicely. I think prior to landing I was told rather rudely to put away my headphones or something along those lines. I definitely did not like that.
Since this particular flight was booked with miles, I have to say I was very satisfied. However, I agree that many other carriers would have offered a much better alternative for SGN-XXX-SFO. My final destination was MEX (I spent two nights in Silicon Valley visiting a friend, but it was not an essential stop that I could have definitely bypassed) and ideally I would have loved to fly SGN-NRT or SGN-ICN with VN, and then AM to MEX, but cost and unavailability of award seats prevented me from taking those flights, which I am sure would have been much better.