Both are great units. The decision can really depend on what unit you are looking at. Are you going top of the line for both or the less expensive DI units?
Here are my opinions:
Humminbird Advantages
-Price
-SI comes standard
-Customer Service
-Can take Lakemaster chips
-Cool digital mapping features like coloring of depth ranges/shifting of data
-Units float
-360 Imaging (price argument above goes out the window with this add on though)
Lowrance
-More range (LSS-2 Units)
-Blazing speed (Gen 2 units)
-More capacity for trails (HB has 50 trail limit)
-StructureMap (Gen 2 units)
-Better clarity (this is my opinion, boths sides argue about this)
-SI can be purchased at a later date
-Custom mapping capable with DrDepth
-Sirius Satellite Weather add on
-5 Year upgrade program
This is all I can think of off the top of my head. I’ll add more later if necessary.
All in all I think you’ll be good either way you go.
I’ve owned a 1st generation Humminbird, used 2nd generation Humminbirds and just recently went all Gen2 Lowrance. Don’t really have many complaints about either one.
For me personally, the Lowrance was the better choice. I think they have better scanning and I do custom mapping. I like their accessories.
Good luck!