The 3 major brands are all quality units (Fish Hawk X4, Subtroll, and Depth Raider). It is all personal preferance. I have used all three brands. I have the Fish Hawk 840 with the X4 probe. My reason is I do not like coated cable. It is more expensive but it is worth it to me. If I purchased a coated cable unit, I would go with the Depth Raider. The Depth Raider has a smaller probe and will cause less blow back on your rigger.