My wife an I flew from San Jose, CA to Frankfurt in September 2018. Here are my personal views on the experience.
Lufthansa operates an Airbus 340-300 on this route (or used to, it has canceled this flight as of Oct 2018).
This direct flight is super convenient for those in the South Bay (we live about 7 miles from SJC and it is way easier than SFO for us). The 340 is a large plane, probably the only 4 engine aircraft operating out of SJC. One issue that causes is that SJC's gate area isn't capable to accommodating that many passengers. If the flight is full (as ours was), then there aren't enough chairs for everyone to sit.
The flight was slightly late (due to late arrival of the incoming aircraft) but boarding and seating was uneventful and we were soon on our way.
Since this is an eastbound long distance flight (almost necessarily redeye), a muslim typically has to pray at least twice (if not thrice) during the flight. Since we were scheduled to arrive before sunset, I only had to make two prayers on the plane. Maghrib/Isha (sunset/night) and fajr (dawn). Although there was an IFE in the seatback in front of me, which had a navigation system, Lufthansa (unsurprisingly) doesn't offer any prayer times, nor direction of qibla. Worse, it doesn't have a forward (or any) camera so if you are not at a window seat, you won't know what's going on outside. Fortunately, this plane is configured with a 2+4+2 configuration in economy so my wife and I had a 2 seater on the left side of the plane so did have access to a window. Maghrib isn't hard to figure out (just wait for the sun to disappear) but fajr is much harder to determine (I hope to cover that in another article). Anyway, restrooms on this aging plane aren't particularly roomy but serviceable. They don't have autosensing taps so making wudu (ablution) is harder.
Best place to pray in economy is the rear of the plane, just ahead of the galley. There are no restrooms there so you can pray there without blocking the restrooms.
Lufthansa offers a vegetarian option for every meal so food wasn't an issue.
Seat comfort was decent (width, pitch was okay, padding was a bit thin but serviceable) so was the entertainment portion of the IFE. Crew was top notch but perhaps not as diverse as it could be. Overall, we liked the flight and are sad to see it no longer being offered.