> could use the cartopy specific ax.set_extent

Ok, here's my best shot at that
https://github.com/pp-mo/iris/pull/9

With a carefully selected lat/lon region, you can get a couple of plots that both look ok.  
The idea is growing on me, but I'm still not *quite* convinced this is a great idea
  -- the usage is still pretty artificial, as the region bounds come from "magic numbers", not the data