I have been screwing around with a Elite 4 DSI for the past 6 months and am not too impressed. It was my first sonar unit and want to give a non dsi unit a shot. I have around $350 to play with and don't have a need for a chart plotter as 90% of the spots I fish are pretty small size wise. If I stay with Lowrance, can I keep the same transducer mounted or are the DSI transducers different? Will be trolling motor mounted if that matters.

The DSI transducers are different. If you want to stay with Lowrance, look at the regular 2d sonar Elite 4, I have one and have been very happy and impressed with it. I went with that over the DSI after seeing a buddys Elite 5 DSI in action on the water and was less than impressed. Mine has the internal GPS and goes for about $300 most places, I think the color 2d sonar without the GPS is about $200. I have no problem with the smaller units on my boat, as space is limited.

The DSI transducers are different. If you want to stay with Lowrance, look at the regular 2d sonar Elite 4, I have one and have been very happy and impressed with it. I went with that over the DSI after seeing a buddys Elite 5 DSI in action on the water and was less than impressed. Mine has the internal GPS and goes for about $300 most places, I think the color 2d sonar without the GPS is about $200. I have no problem with the smaller units on my boat, as space is limited.

Yeah I was leaning towards the 4x or maybe the 5x but don't think I need that big of a unit (STS) in my 10' pond boat

After a helpful PM, I'm leaning towards this model.

http://store.humminbird.com/products/600667/346c_DI