E-callers work well. Are they the best thing going, not in my opinion. They do, how ever, compliment a good set of hand calls. The best E-callers on the market are very pricey! If money's not a problem, I'd suggest a Fox Pro oraMinaska! They both have a great selection of differant sounds, enough so that you could effectively call predators with only them, and no hand calls. They are pretty much, push a button and play! Some play them constantly, and other hunters turn them on and turn them off!
I'm stilla bit old school, I like my hand calls better thanany E-caller that I've heard! BUT e-callers work, so says a lot of predator hunters!