Re: Depth finder
Don't know about the Lowrance but I have the Helix 7 and I have no complaints thus far.
The 9 will give you more options than the 7, such as, building your own maps and of course the bigger screen. Kinda, sort of, whished I had that map thingy capability if it does what it suppose to, but for now, I can record then plot on my 'puter any routes and/or waypoints.
Side imaging and down imaging is a real asset once you learn (I still am) to use it. Learning/practicing with all the different features gives ya sumthin to do when the fish ain't bitin.
Good luck with your choice.
Give a man a fish and you will feed him for a day; teach a man to fish and you will feed him for a life time. ~Anne Isabella Thackeray Ritchie (1837–1919)~
Old fisherman never die; we just smell that way.