I use the M6. I use the 5.3 on it 90% of the time. It gets just about as much depth as the large coil. It is excellent in trashy areas. I cant say anything about the shooter coil,never used it. But if you have mineralzation problems then the shooter would work better than the eclipse. One nice thing about the M6 and MXT, you get a small coil and get in a trashy spot, you can lock your tracking after you ground balance.
I tell you another good small coil Ive read and heard so much about and thats the accelerator coils.
HH
John