I can't quite figure out whether the thread here is referring to X interpolants or K interpolants right now.  But Quintic is definitely preferred over Lanczos for K interpolant.  And for X interpolant it is somewhat a matter of what you want to define as the meaning of your sampled image.  At the same kernel size, Lanczos puts slightly less power into aliased frequencies.  But it does have the issue of not exactly reproducing a constant background (although very close with the flux-conserving tweak, which also slightly worsens the aliasing).