You just don't need a lot of weight to get deep in open water. General rule I follow is, I use the least amount necessary to get the job done. I typically want a slow fall through the water column so suspending fish get a good chance to look at the bait as it passes them bye. With plastics I often use no weight, 1/32, or 1/16 seldom more then that if the conditions are good. Conditions that will cause me to increase the weight are: 1). wind, 2).thick weeds, 3).little fish attacking at the surface, 4). strong current, and 5).certain fishing techniques.
Regardless of the weight, it will get to the bottom, it's just how fast you want it on the bottom. If I am in search mode, I typically want to work the whole water column, not just the surface, mid range, or bottom. To do that with plastics, I need a light weight and a slow methodical fall. This gives fish, at all levels, a shot at attacking the dying bait. If I predict big fish hugging bottom structure, I may go with a good size jig, or a jig and craw. It will hammer the bottom fast, and hug the structure while working back to the boat. Before doing that I have to have a good understanding of where their hiding.
Bass fishing is all about knowledge, strategy, and patience. You have to have a game plan, and a willingness to adjust to what they want that day, that hour, that location! Always remember that no two days are the same, no two locations are the same, and no two conditions the same. Its up to you to figure them out, and be willing to adjust!