I bought the hds 5 and by far it's the best sounder I've had. I was getting excellent scratches 150 down to 300 ft last outing. Too bad I found out they were hake
I have found using default settings is fine for water up to 200 feet with the algae bloom in full swing, but after that I turn off auto sensitivity and set sensitivity accordingly, use custom depth range with no more than a 100-150 spread. I also set to no noise filter, high or medium surface clutter and 2 or 4 X scroll speed. Once in a while with the "algae bloom sttings" I use, the sounder looses its mind and thinks any given depth is bottom and holds that idea until I repower, but it's an easy remidy and well worth the high end readings I get in deeper water when fishing deep or shallow.
It took me a few days of playing to find my settings, but I'm more than happy with the best "view" I've had while fishing the bloom.