Do try them again in 20 years. I'm sure you'll have another very different experience!

Not, I have written them off, just as I have all US airlines.

lol, thanks for the warning! I am sure that profile option will be prominently displayed in the app!

Yesterday I got the on-board upgrade offer on my flight to Accra.

Once airborne and the "fasten seatbelts" sign was off the economy class purser came to me and offered me to use miles to upgrade to the "last available seat" in Business. He was able to see the amount of miles left in my account and my status. I agreed and he helped me with my luggage (nice touch).

When I arrived at my seat I got a few strange looks from the FA's who then (three independently) congratulated me with my upgrade. After a while I asked for the amenity kit and menu and enjoyed a smooth ride on the A330-300.

Is weight distribution the reason they wait with the upgrade offer until after take-off?

They first have to look for non-revs. ;)

why the strange looks and the congratulations? Very weird reaction especially the congratulations part.

Probably busy with pre-departure items before take-off

How many miles did they charge you?

Nice! Just curious, was the upgrade at the same miles amount when buying it ahead of time (if available) or at a discount?

Agreed, made me feel a bit awquard as well. Even about them being a bit patronizing about economy class.

It was the same miles amount.

The BC seats in the A330-300 are nicer than on the A330-200 so it as a good product experience overall (too bad the salmon was no longer available).
Think if KLM would decide to offer the upgrade whilst at the ground it would be better overall experience for myself and the crew.

Also I think a miles discount could be justified as you cannot use the cabin luggage freedom for BC, not enter the lounge (assuming you're no gold or plat), use the BC boarding and you miss the welcome drinks :)

Bottom line is I was happy I got the opportunity to upgrade in the plane.

In case it's the last seat in J (or perhaps the last few seats in J) they will not easily offer them for upgrade before checkin closes, since they still may sell it at the last moment (or use it for a last minute rebooking with full J fare). Such things happen quite often. After checkin closes, proposing upgrades for miles at the gate would be too cumbersome. Hence, the iPad driven inflight upgrade proposal.

Understood and agreed. Instead of "on the ground" I should have said "check-in closed, people boarding/boarded, plane still at the gate".

My experience says different. I have had flights successfully upgraded with miles about 3 hours before departure at the AMS ticketdesk.
What I often saw that in the morning one single middle-seat would open up in C which was then up for grabs with miles...

In my case it was a no-show so the seat offered to me only became available after check-in closed.

Not necessarily. In the Good Old Flying Dutchman Days, RoyalWing members who wished to upgrade on a flight where WBC was sold out would simply fill out and sign a form in the RoyalWing lounge. The form was handed to a gate agent, who would issue a boarding card for a WBC seat if there were any no shows when boarding closed. The form was then sent to Flying Dutchman, and the points were deducted.

Johan