RE: Kentucky style green beans
I've never tasted Allen's, but I AM a vegetable gardener, so here's a bit about green beans.
ALL beans grow either as bush or pole, or both, whether they are grown for fresh use, or for dried beans. There are several reasons for growing bush beans rather than pole beans. Bush beans all tend to mature at the same time, so harvest is fast and complete, and the freezing or canning can all get done at one time. Also, there are more varieties available in bush beans than in pole. I prefer pole beans because they produce continually until frost, lots to eat regularly, with some left over for freezing and/or neighbors.
Italian Green Beans are Italian Green Beans, and Romano is one classic variety. They are always flat and broad podded, and have a distinct flavor and texture. They're usually more fibrous than an American green bean.
Kentucky Wonder Green Beans are a typical American classic variety of string beans, grown for many years, and the parent of many other varieties. (The other ranking American variety is Blue Lake.)
The bush Kentucky Wonder may well be flatter, but it's still a Kentucky Wonder, not an Italian Green Bean. I don't know about the bush variety, because I prefer pole varieties. As we speak, my Kentucky Wonder beans have been flowering seriously for several weeks, and I'm just starting to see my first beans, tiny things, between 1/4" and 1/2" long.
Both Kentucky Wonders AND Italian Green Beans taste delicious cooked "southern," i.e. with the addition of bacon grease or ham fat, cooked to a fare-thee-well, and with plenty of pot liquor to slop onto one's cornbread. Subtract the cornbread, and you have classic Pennsylvania German green beans, though they wouldn't have been likely to grow Italian beans.
There, more than you EVER wanted to know about green beans!