Garmin Striker 7 or 73sv

I am debating between the Garmin Striker 7 vs the 73sv (non chirp) and wanted some opinons on what would be more important the mapping or the chirp. I alraedy have a 53dv at the bow that i can link the Striker to so maybe the chirp is more important but I wanted a few opinions before I buy.

Pretty arches (with CHIRP) are cool for internet posting ...

But the ability to see and relate your fishing time to Contour lines with mapping are invaluable to a crappie fisherman ...

Rickie