Is the 07 LOW Navionics chip out yet? The Newer the better detail for sure in the Chip game. I know both LAkeMaster and Navionics have New LOW chips coming out and I can guarantee they both will be great products for me the big difference is the Lakemaster Chips load faster and more importantly zoom in farther which is really nice for hugging the contour lines when trolling.
At this point in time excluding the New chips if your just fishing the U.S. side it's pretty much a dead heat between the two chips detail wise from what I'm hearing.
So I'm guessing you already have either a 07 Lakemaster MN or the 07 Navionics Premium North chip both have BS and AL in High Definition 1 foot contours?