Transit in the USA is terrible. Even on the same plane service LHR-LAX-AKL vv you have to clear immigration (full fingerpring and eyescan treatment, visa required if applicable) even though you are held in a secure airside holding pen. Why would I subject myself to this when transit in asia is painless?

If I am not visiting USA (or somewhere that I have to connect through USA) then I try to avoid transitting. Pretty hard on RTW tickets though. I have even routed through asia to Canada to avoid LAX transit treatment. With NZ's new AKL-YVR flight avoiding USA on RTWs has just got easier.