which has been known to work better?

I like them both, use the electronic to call them in from long distance and a mouth to coax them in close...

which "works better" is a very subjective question. As far as just bringing predators toward your location, they will both work, many would argue that hand calls will bring more, but many others would argue that the ecaller will bring more toward you. BUT the biggest difference and probably the #1 reason to use ecallers is that it gets the sound away from the hunter, and if done right, will be a significant advantage when it comes time to kill the predator. Of course the ecallers of today have such an array of sounds to choose from, many of which can't be produced with hand calls, which isn't really necassary unless you're hunting coyotes that get called alot with hand calls.
No matter which tool you use to call coyotes, the hunter still has to set up his/her stands properly, or the out come will be the same, a low kill to called ratio.

Thats a good way to look at it, I use both, but there is a felling of saticfaction for me to get one with the hand calls. The first coyote I ever called I did'nt even mean to. I was hunting squirls, and got a dog to come up. Scared the mess out of me and my dad, but I turned and gave him a full patern of dove load at just a couple of yards,, that was it I was hooked. So with an E-caller it mat bemore true andstate-of-the-art, but nothing like gettin the interst of a dog with a hand call.

Here in Michigan we have our best success getting them to howl with mouth calls, but while hunting we have our best success use the fox pro.. Walt

personally i prefer the mouth call but maybe its because im cheap and dont want to spend the manoey on an ecaller

i have an fx5 but it seems im always useing my mouth calls.

thanks for the input i'd like to get an electronic call eventually but due to lack of money i bought myself a knight and hale lead dawg howler and rabbit in distress call.i'll probably take it out and give it a try this weekend.

Oh no! I'm not the kind of guy to rip on much, but the knight & hale lead dog......is about the most worthless call a guy could get. It may work for ya somewhat, but I got one and it is not worth the couple bucks I spent on it. I think if you got a primos you would be more happy with it, hotdog, littledog, tallyho and the little green squeeler call will do much better. The verminater calls are good to, even tho I don't have any of them.