Used just 1 lb of 21-24 shrimp and it was excellent.
I didn't have any feta, but it was fine without it. Double the dressing even if you don't use all of it because a pound of angel hair makes a lot of pasta for this small amount of dressing. The addition of the orange provided an interesting sweetness to the shrimp.
This is a wonderful find! We live in an RV much of the year, don't like to cook seafood inside--so I marinated the shrimp in first 6 ingredients for @ 6 hours, then cooked shrimp on the grill. Did the pasta and sauce inside, then added the shrimp from the grill. Everyone loved it. Organic greens with a vinegar & oil made a perfect accompaniment.