I got a 10x12 sef coil on the way, I also have the 6x8 which I use 85% right now. I really like the way the sef coil separates in "iron" soil, so I'm hoping the bigger sef will perform just as well. I hunt a lot in "iron" soil and the pro (stock) coil is more suited for clean soil, IMHO. The main reason for the bigger sef to me, is to cover more ground and get more depth. Right now I can pull dimes at 8"-10" with the 6x8, so I'll see how the 10x12 works hopefully better. I'm using the Safari now but will be getting an E-trac in a few months and will use these coils with it. Anyone else using the 10x12 sef, give some opinions...?