I've always had Lowrance but have been seriously considering switching to Bird units and getting the SI.....My question is that I've talked to a lot of guys that have the 7 series Bird's and say they are too small for the side imaging and they wound up selling their 7's and upgrading to a 9 series...Would I be better off to go ahead and buy a 7 series or save up for awhile and get a 9?