AMS / AV + would
almost certainly be easier than STV, which would require huge constituencies for rural areas (and even under FPTP, there are inequalities in constituency membership because of the difficulties caused by excessive size), but then a whole new can of worms would be opened up concerning how to set the ratio between
corrective «top - up» MPs, and constituency MPs, plus a whole load of other factors such
as whether to allow dual standing, whether the two votes should be two choices or interconnected, whether the list should be open or closed, etc., etc..