I use a cheap decoy and it works well enough. I have had deer nudge it. I did have it fall over with a huge gust of wind when the gobbler was 4 feet from it. I had not shot as I was full draw with a bow and needed the bird to step out from behind a log.

I always use hen decoys since I am on public land and I don't want anyone to mistake my decoy for a live bird since at a distance they all look good enough to fool someone.

The thing that made the biggest difference for me was to learn to properly use a mouth call. But I have had success using box call as well. I call very little and use a combo of box and mouth call as it lets me change things on the fly. Plus I there are just some calls that I can do on a box call and cannot get right with a mouth call.