The No. 1 problem with decoys is knowing when to use them and when to keep them in your vest. The answer lies in the nature of turkey decoys. They’re not so much an attractant as they are a visual reassurance.
In spring hunting, you engage gobblers via sound by calling. Whether you answer a tom or get him to gobble, you’re telling him there’s a hen nearby that’s ready to breed. If everything goes well, he’ll come to check things out. Depending on the situation, decoys can reassure a gobbler that the hen is really there.
Sometimes, that reassurance is unnecessary. At a perfect setup, you will not see a gobbler — and vice versa — until he’s in range. Ideally, there will be a small terrain rise, brushy obstruction, bend in a logging road or something similar that prevents the gobbler from seeing the source of the calling until he pops his head up at 30 steps.
In such situations, you don’t need a decoy. The bird cannot see the hen, but, because of the terrain or other factors, he knows that’s not unnatural. When he pops over a rise or around a bend in the logging road, he’ll almost always stop and crane his neck to look for the source of the calling, which should then be visible. If he doesn’t see it, he’ll usually leave fairly quickly. However, you’ll no doubt have sent a swarm of shot his way by then.
Of course, you can’t always find those perfect setups. Turkeys often use open areas — meadows, open bottoms, pastured woods, agricultural fields and open benches of mature timber — where they can see long distances. If a longbeard comes to your calling at these spots, he might approach to within 80 yards, look for the source of the calling — he’ll know exactly where it came from — note the absence of a hen and high-tail it elsewhere.
So in open spots where you — and turkeys — can see long distances, it’s wise to use decoys. If a gobbler approaches and sees a hen or breeding flock near the source of the calling, it tells him everything is natural, and that the hot little hen is right where she should be. That doesn’t ensure he’ll come in, but it helps.
Regarding strutter decoys: Yes, they're very popular nowadays, and I've seen them work like charms. I've also seen many gobblers run from them. It's all about social hierarchy. If the boss bird of an area sees a strutter decoy, he'll likely charge in for a fight. If a picked-on 2-year-old sees it, he'll likely run away. Take your chances.