I've grown Alderman twice and I like them a lot - you get loads and they taste lovely. I grow them in 2 rows like Eristic, supporting them with netting attached to canes.
I've found that they don't keep on coming forever like beans, after about 6 weeks or so of cropping they conk out so best to plant several lots in succession, say about a month apart.
I've also found that they don't seem quite so susceptible to pigeon attack when young as shorter varieties - this may be rubbish but that's how it seems to me! I'd definitely still protect the seedlings though.