Does the Oblivion graphics extender help alot?
The cheeky (yet accurate) answer is: "That depends on you!"
More helpfully, I hope... It provides you with a set of shaders that you can use any number of, and tweak to suit. Some of them outright improve image quality, such as some form of anti-aliasing, and probably screen-space ambient occlusion too. Most, however, are purely a matter of taste - they modify, without objectively boosting clarity, increasing resolution, or anything like that. WIthout a doubt though, OBGE Liquid Water is a vast improvement upon "vanilla" water, and in fact, surpasses any other water modification to date.
By far.