I take 6-8 long haul flights a year and as I have to pay for my own ticket will almost always opt for the cheapest. This means I may use 6-8 different airlines a year.
I have no problems using KLM and they do seem to give consistent service, unfortunately, mediocre. The onboard service is always the same, food ok but served with a scowl. Don’t mind that, I’m not looking for an onboard romance. This is offset by them always giving me an extra vodka should I want one.
The two times there has been problems have been dealt with in an exemplary way. First time my flight from Shanghai was cancelled. I was asked if I would fly the next day with KLM or would I prefer to fly that day with another carrier. I opted to fly with Virgin and got home with just a couple of hours delay. The second time was when there was terrible disruption in Schiphol due to strong winds. There were massive queues to rebook so I phoned my daughter in the UK to ask her to rebook me. She phoned back within half an hour to confirm my flight the next day.
So for me, KLM are just fine.