They're pretty much the same workout as any other fly.
I don't do these, though because they're uncomfortable, and IMO they're an inferior chest exercise. They put the pec at a slightly weaker angle and rely more on the anterior delt, which is exactly what you'd want to avoid at this point. (The only reason I do flyes is to specifically target my lagging chest.) Placing the runners at the highest position and doing the fly motion while bent over seems to isolate the pecs the best for me.