Transducer selection depends on a few factors - how deep do you typically fish and what techniques do you typically use to pick a couple. For example, the cone angle of the 8 will allow you to see a swimming lure such as a jigging rap or a flutter spoon in somewhat shallower depths of 12' or less, whereas those lures may move outside of the 10's cone angle whilst you're working them. If you're mainly jigging for pannies using a teardrop where a wide cone angle isn't an issue, then the 10 will give you a somewhat better (smaller) separation reading over the 8 from what I understand. I have an 8 on the Garmin unit I have - haven't used a 10 - and I would rate it as a good all-purpose transducer that can cover most ice fishing techniques. If you typically fish deeper water, say 25' and deeper, I would opt for the 10.