I have bought and used practically every type of hearing aid and used them for turkey hunting over the past 40 years or so.
For most turkey hunters, the Walker Game Ears are the optimal choice. They have several "grades" and all are good but I must say the lower priced ones seem to work just as well for me as the more expensive ones.
A hunter must be committed to using the devices. They can bother you, drop off your ear, are easily lost and magnify every chirping bird, log truck, and your buddy's yelping. BUT, if you have trouble hearing a distant gobbler, they can revolutionize your hunting.
Dollar for dollar, the Walker Game Ear products are the best option for a spring hunter (and I have paid as high as $2000 for hearing aids...lost them...).
Muffs vs "over the ear" vs "in the ear"? I own all of them and I am an "over the ear" man.