I have the 737. I really like the side by side 60 deg and 20 deg screen. You can really zero in on structure or schools of fish with it.
The 60 gets you to the general vicinity and the 20 deg gets you right on top of your target. When the school moves out of the 20 deg cone but is still in the 60 you know it is still close by.
You can see your jig with the 20deg cone if you drop your line beside the transducer.
I have not found much use for the two 45 deg side beams, but I believe they may be useful for trolling.
The multiple screen options are a plus:
1. 20 deg on top, side beams on bottom
2. 20 deg with real time window
3. 20 deg with zoom
4. 60 deg and 20 deg side by side
I highly recommend this model, the B&W screen is easily visible (unlike my prior unit).