The 10" DD weighs 14.2 oz and the 11" DD weighs 14 oz. The longer cable on the 10" is what makes up the extra weight so they are nearly identical. With the 11"DD you have most of the weight on the end of your pole, but with the 10" more weight is distributed up the pole with the cable, so it actually feels like a lighter coil.
I use them both and like them both, but there is an advantage to the solid 10" coil when hunting stuble, both in snagging and in getting between things easier. You have nearly the same sweep path and nearly the same depth, but a narrow width giving you really good separation. For most sites I hunt, there is a lot of iron, but if its not too bad I will use the 11". If I get into really heavy iron trash, I like the 10" for better separation. I really like them both.
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