I've grown clemson spineless, hill country and burgundy (and observed my neighbor growing star of David), and burgundy is the most prolific. If you give it enough room it almost looks like a tree, with many side branches. The added advantage is that you can pick the pods when they are quite long and they are still tender. They turn green when you cook them.

I grew hill country okra a couple of years ago and was not very pleased with it. It is spiny, the pods were not very tender, and the plants were huge and diffcult to harvest when tall. The worst part is that it's not spineless, so if you are going to grow it you need to wear gloves.

In my cool climate, Annie Oakley has been by far the best-yielding. I suppose that may not be the case everywhere. Clemson Spineless is a dud here.

Grew CS when I lived in SoCal, and was pretty happy with it. Kept me in okra all Summer, but then, I had a lot of plants. It grew to over 6' tall there, with few branches..

As mentioned by Slimy_okra, the choice of okra may depend upon the location & climate. In my Northern location, summers are hot, but short... so I need a variety that bears quickly, and can tolerate a few cool nights. "Pentagreen" has proven to be reliable for me. It bears quickly, and will branch heavily if given space (I use 18-24" spacing between plants).

Tried to grow CS when I moved here, but it doesn't do well in this climate. That was the case for quite a few varieties that I tried, including some that were described as "good for the North". Most would start to get leaf browning just about when they started flowering, and only bear for a week or two before dying. "Pentagreen" has proven to be more robust... I recommend it for those of us who get snow & summer in equal measure.