Had a pretty good test of the 10x5 today. In gold mode it's super sensitive, way more susceptible to emi than the minelab 6". Almost like an SDC when the wind blows or a truck with a CB radio goes past. Probably gets a bit more depth on the shotty+ sized bits but is only as sensitive to species in a tiny little spot about were the coiltek logo is on the toe of coil.
I probably wouldn't use it for gold detecting, but for coins and relics it's a weapon. Old mate got 2 thrippies, a sixpence and a penny in a spot we've both hammered a few times. It seems to have the target separation of the 6" coil and the depth of the 11" combined. He's sold his 6", but after today he's wishing he kept it for gold.