depending on the frame, an electronic grip can reduce you trigger pull to the lightest touch. co you can fire at stupidly quick speeds. and also enables quicker snap shooting. its a speed thing. the only problem is if a mechaniccal trigger goes wrong, you can fix it easily (usually). with an electric one, without a degree in electronic engineering, you will be pushed to do anything if it goes wrong. AND its another battery that will run out at the wrong moment.
just my point of view.