I use a scope. I've been using a 1.5-4.5 scope since 1996.
My eyes were such back then that I had stopped being able to see the front pin and the turkey. Over the past 20 years or so, my nearsightedness has gotten better. However, I've kept the scope on. I like it.
About the only thing I can say against the scope is that it narrows my focus, and I lose depth perception. I've had a couple of instances where I got down and put my eye on the scope and the gobbler moved out into the field further than I was expecting.
Once, I had a gob coming down a fenceline, and as he passed behind a large tree, I got my gun up. When he came out the other side, I was expecting him to be less than 20 yards in front of me. He'd run out into the pasture and I had no idea of the distance. I took the shot at 80 yards, and managed to drop him. It wasn't enough to kill him. As I was picking myself up, he popped back up and started walking away. I had to chase after the bird and finally cornered him about 200 yards away.
Lesson: Always keep your head up enough to see the bird without the scope before taking the shot.
BTW: My eyes have improved enough that I'm going to give it a try with my Brown Bess this year. It has a 43 " barrel, and I can see the bayonet lug just fine.