Of all the factors that would lead me to jump ship - it is economy class seat pitch on their partners along with destinations.

KLM has an excellent partner list of airlines that go where I go (Malaysian, GlobalPass). I love Malaysian because of their 34" Y class pitch for long haul. KLM always sits me in select economy.

The new Skyteam alliance will give me access to Korean which also has 34" seat pitch.

As far as Know Star Alliance has lousy pitch in the back (SQ) unless you have E+. One Worlds CX is unbearable for me.

I am 6ft 3" . It makes a difference to me. I rarely purchase long haul business Class.