You’ll like either one, honestly. The LX-6/7 is really neat, as is the FL-20/FLX-28. Play with both and decide on your own which one is better for you. I decided the FLX was better for me and now i’m second guessing my choice due to the ProView transducer. I fish a lot of shallow water (4-8′) and the ProView is just too powerful, even with weed-mode and low power mode active. Other than that, it’s the best unit I’ve owned.
I had the same issues trying to use the weed mode with my 28. I switched to a tri beam and it seems to help. Still hard to beat my 22 in shallow water or weeds. Get one of your buddies to switch you transducers for a trip and see if it helps. Any vex transducer will work on your 28