The most frequent opinions are that Lowrance has better DI and Humminbird has better shallow water SI...

This can be quantified somewhat by...:

*The fact that Lowrance has a dedicated "down pointing" piezo (DI in the HB SI units is computer generated from data received from the SI piezoes)...

*The fact that HB's 455kHz covers a full 180° (Lowrance widest coverage is about 130°)...

If you vertical jig...the Lowrance "down pointing" piezo would be of benefit...

If you fish a lot of shallow water (<8ft)...the HB 455kHz 180° coverage would be of benefit...

Rickie