Is 13 unlucky? Might as well go straight to a 14 speed cassette then.

Start with a 11-32 11 speed, add a 10, 37, 42 or 44 along with a 42 or 44 ring and you'd have all the range you would need for any conceivable scenario, short of scaling the alps with a tourer loaded to the gills.

I like the 12 speed: when will shimano introduce theirs? They claim it's not something they're focusing on right now, with di2 being their focus.