EZ, I know what you mean about not always feeling the thump from some of the bigger ones. It us hard to tell some times. I am seeing the fish image merge with my jig image. Sometimes it is a bite and sometimes not. I suspect that at times, they are sucking it in and spitting it right back out. I have gotten to the point where I am raising my rod tip slightly once the images have merged for a bit. This will sometimes set the hook or make them take the jig. Be careful though. I have also learned that what seems like a small twitch of the wrist to me has exaggerated effects on my jig. On live scope I am seeing that a small one inch or less flick of the wrist can make my jig jump up in the water column by 2 or 3 feet! This spooks them away. I never realized that what I considered a small movement had such an enormous effect on the jig. Make very small and slow movements when you see the images merge.