You guys or gals that have the echoMAP 73 SV chirp units, what do you like about them and what do you dislike about them? I'm highly considering pulling the trigger on one for my small flat bottom boat. I don't really need the bigger screen sizes 9" model as I'm afraid it could get broke easily. I like the fact that I could add the panoptix transducer whenever I'm ready too. Are y'all happy you purchased this unit?