I'm confused about people who say SAS is reasonable about carry on rules.

SAS check-in in Copenhagen is now rigorously enforcing an 8 kg carry-on limit - no exceptions, no arguments: "This is what all airlines all over the world do" and "It's for your own safety, sir." I've connected thorugh London to Copenhagen on business 12 times in the past few months. Every single time, SAS in Copenhagen forced me to check a normal sized roughly 10 kg carry on bag that SAS in London allowed. Frequent flyers with tight connections should beware.

Since SAS handles check in for all Star Alliance airlines in Copenhagen, the only way to have a reasonable carry-on allowance is to use other airlines. KLM has never caused me problems with carry ons.