Hubby has a new job taking him from US to Europe/Africa fairly often in paid business class. His work seems to be booking him on KLM most frequently (we don't get a choice in carriers), so we're debating about whether he should earn the miles in SkyMiles or Flying Blue.

In general, we use miles to either bring his family to visit us in the US or the two of us travel internationally together. I had hoped we could accrue on United, as no SkyTeam members seem to fly into Sarajevo, where his family lives, but it's unfortunately not an option. (*Alliance is actually pretty good out of SJJ.) Any suggestions about SkyMiles vs. Flying Blue?

FWIW, I have over 400K SkyMiles accrued from when I used to travel internationally a lot, but those now seem fairly worthless when we try to cash in for anything other than US domestic travel. So I'm not eager for him to accrue a bunch of SkyMiles that also end up being worthless. Would appreciate your thoughts!