Lake LBJ

I have a buddy coming up from Dayton week after next and we are going to be doing some fishing.. Heck, a LOT of fishing.. LOL And, one of the places we want to go is Lake LBJ to do some ultralight perch jerking along the shoreline and maybe drift for cats. What can anyone tell me about the bottom in that lake? Is there any amount of vegetation or is it pretty much like all of the Central Texas lakes with a bare rock bottom. Neither of us has fished that lake so any info on general decent areas or parts of the lake to fish would be appreciated. He only makes it up here about once a year and I would really like to put him on some fish.