I have been using my Etrac with just the stock coil this past year, however I have a new 4x8 SEF coil I've never tried and never put it on my Etrac at all this past year. Now... I have a home built in 1814 that I've been over a hundred times as well as my buddies 1800's home. For those of you who have the smaller coils, do you think they find coins the larger ones miss? Just wondering what you've discovered using the smaller coils. Thanks.