Tennessee Rob

I have played with them and to be honest they all look good during demo... I have a Eagle fishmark 320 and it looked good during demo but now that I have it on th boat it is not as good as in the store. I was wanting to buy a better one to use at the console that will show me more detail. However i just don't know what is the most important parts to a unit.

Ok I have been setting aside money with the whole purpose of getting myself a better Depth/fishfinder and maybe even a GPS with mapping... In looking at different units both in store and online I am just not sure what I should be focusing on. I would think that Lowrance or Hummingbird are the top two right? then what about Display Resolution? Sonar Frequency? Sonar Output? Dual or signal sonar? etc. What is most important? then in a GPS what do I want to make sure a unit has? thanks..!