Display agreement works well for both companies. Samsung can produce LCDs like no other and Apple needs more LCDs like no other. Though Apple should not rely on any one company for a critical component. I wish Apple could use a US based company for more of its components like LCDs but Asia production costs are too low to try to compete with.
I think LG makes a better display then Samsung. Especially the ones they are providing to Apple.
Now on this subject, I don't think Apple wanted to pay the increased cost of the displays from the unforseen increase in production costs. The increase was only $1.5 Billion.