My grandparents had a cabin in the Diamond City/Lead Hill area and when I was a kid we would go there several times a year for fishing and lake fun. Many fond memories of that lake. There used to be a swimming dock over the hill west of the marina and it was loads of fun. It was pretty large, had a "kiddy" pool in the middle, and even had a diving board. I learned to swim there. Sadly, it's mooring lines broke during a bad storm one year, it floated across the lake, broke apart and wasn't rebuilt. I also learned to ski on that lake...got up on my third attempt. It's true that when the lake reaches flood stage, the marina at Diamond City is in peril. The floods we've had in the the last couple of years seriously damaged the marina dock and I'm not sure they've rebuilt it or even plan to.
Fishing on Bull Shoals used to be much better than on Table Rock, at least in my experience, but I haven't fished it in ages so I couldn't say now. You mentioned gar...the best "fight" I ever had with a fish was when I caught a 3' gar on that lake. I had it on the line for about 45 minutes, finally getting it up and into the boat. Surprisingly, it's teeth didn't saw through the line. I wasn't about to try and retrieve the hook from it's toothy mouth so we cut the line and tossed it back. When the white bass were running on the shoal across from the marina, we'd put a silver spoon on our lines, cast out into the middle of 'em and reel in a bass with every cast. We'd do that til the bottom of the boat was full and then motor back to the dock for a long fish cleaning session. At night, we'd go out to fish for crappie (best tasting fish in the lake)...we'd pull up to a bluff, tie off on a tree and hang lights out over edge of the boat to attract the lake minnows, then we'd drop our minnow baited lines over the side and catch our limits every time.
After my grandparent's passing, the family kept the cabin in the family for many years but finally sold it just a couple of years ago.