My only opinion on the subject is no, that is unless your fishing near shore or shallows. I have a Helix with down imaging and use that perchin' . Trolling seems a not needed item in the long run. I have never used the gps/ff combo either I have to keep them separate, but that's just me. If it is a must to have gps/ff and going with the DI I would go with the 7 it has as nicer screen size when splitting screens.

Gene