As a stat freak, let me tell you that OOTP is nothing short of amazing. The OOTP engine is infinitely more realistic than 3D games like MVP and MLB 2k6, and, best of all, you're not forced to continually tinker with slider options in order to produce realistic results. If playing with ficitional rosters isn't your cup of tea, there's always fan-created rosters that you have the option to download. There's currently one on www.ootpmodsquad.com
Keep in mind, that upon release and to the dismay of many fans, OOTP 2006 was nothing short of terrible. Several game-breaking bugs were evident, and the AI was downright poor. Thankfully, the game developers have released several patches since then, restoring the game's original state of greatness. In fact, another patch is tentatively scheduled to be released on the 20th.