Arklier, good points about the resolution, that would probably be 3rd on my list of important features, and in this price range ($250) the 320 DF is hard to beat, my only hesitation with the new Eagle's is I'm not sure that they have got the bugs worked out, we've sold alot of them in the past month but I haven't got any feedback on them yet. As for the Fishmark, its a very good freshwater unit but too weak (188w RMS) IMHO for serious saltwater use. Would recommend 300+watts RMS for saltwater use.