I'd never flown KLM before and was excited to do some comparison.
My boarding pass indicated I was Zone 3, and there was no one else who got in line for Zone 3... so I was boarding the plane all alone. Gave me great opportunity to stow my backpack properly, settle with my book, etc. We did a "bio metric check in" - basically we took off our masks and they took a photo... not sure how this tied in with my boarding pass, but oh well.
The seats are huge! At first I was thinking that I'd been put into a different class than I usually fly, but it seemed all the econo seats were huge. And the leg room was great -- it's almost like the seats sit higher, so you have room to move your feet.
I overheard an attendant telling another passenger that this flight was less than 1/3 full. This is apparently why the Monday direct flight was cancelled. With so few Americans being allowed to travel into Europe, the alliance came together to provide the service of flying across the pond without unnecessarily sending empty planes. It is just more efficient to fly a fuller plan to Amsterdam and then route some passengers on to other destinations, than to fly several basically empty planes from the US to Europe. Perfect business sense (but poor execution/notification, imho).
After we got underway the attendant came through asking, would you like to move? Basically, the plane was so empty that we each could have our own 3- or 4-seat row... so we could lay down to sleep. Ummm, yeah, absolutely!
The drink and food service was different than my usual experience as well, but not really sure if this is a KLM thang or a COVID thang. Immediately after we were in the air they came by with a single cart. "What would you like to drink?" and "Would you like a meal?". It was not assumed you would actually take a meal... and there was no choice of meal. It was pasta with cheesy sauce and a mystery sprinkled on top, a green salad with a sweet dressing, and a cake with fruit filling. Not bad. They blew through quickly asking if you want tea or coffee. And then they blew through giving a ziploc with squishy things inside (the lighting had starting dimming so I really couldn't see)... What's this, I asked. Food for the rest of the trip... basically breakfast... OK, and then the lights went out... I think it was 8:30-9 at this point.
The flight to Amsterdam is only 6-6.5 hours, so the lights came back on at about midnight EDT. We scarfed our brekkies of cheese sandwiches with dijonaise, and sat back for a smooth landing. 7am and pitch black in Amsterdam.
Overall I'll say that I enjoyed the flight, but I'm not sure how much of my enjoyment was due to KLM and how much was procedures modified due to COVID. I'll definitely fly them again.