Boone,
I heard the windshield theory too. The first unit I bought worked the same behind, on top of, aside, etc the windshield as if I held it 2 feet above my windshield.
The second unit (the one I have now) worked like garbage the first 1/2 day. Then it seemed to figure out what the heck it was supposed to be doing and it’s ran great ever since.
I was talking to another IDA’er at the gun club a few weeks back and he had a very similar experience as I had. Additionally, my uncle has a 334 and the first unit he had was garbage. Lowrance replaced it and it ran awesome (like mine) on Lac Seul in July.
From all that I can only start to lean towards thinking that the newer units are actually improved. If it works on the ice for me this winter as well as it’s working now I will be one fricken happy camper.
I’ll be interested in hearing how yours turn out. Also.. one more thought… if you can, check the date of manufacture on the unit they are equiping your boat with. Might give you an indication as to your success.
Goodluck!!