It depends on speed, species and depth you will troll them at. A small flutter spoon is great for flat-lining. A magum spoon will perform well off a downrigger down 5 ft or more. The middle sizes will do both. I personally like FLT, Michigan Stinger, Yeck, Dreamweaver and Moonshine. To me, the NK's seem a lot heavier than the other blanks. But people do well with those too. Some perform better at slower speeds...and some better at higher speeds. Although, most are very speed tolerant and will fish good at different speeds. Get a few different brands and let the fish decide what they want that day.