A lot of guys dig signals as long as there is a good response from one axis,then an axis 90 degrees to that. When hunting in places where there are many targets per sweep,that stock 11" coil may pick out the signal,part of the signal or none of the signal due to other stuff masking it. With a mid sized coil like that 8", the scenarios gets better,not as many things under the coil at once,still it gets great depth....close to stock,if not the same,depending on the mineralization of the soil. A sniper coil,around 4-6",will be as good as it gets for separation and again,some get very respectable depth. A lot of guys who are serious about the hobby have muliple coils,if not multiple machines with multiple coils.
There is one thing that will get you many coins...go out and hunt. Don't spend a lot of time trying to figure out every nuance of everything and over analyze things. Go sweep old areas of old properties with as big a coil as the conditions allow. THAT is how your coin count will go up,not worrying too much about other things. Keep the 8",get a sniper at some point and go hunt hunt hunt! I used to spend too much time preparing. As long as the site has potential in the first place,you have a chance.
HH
Kevin