All stats are imperfect and all stats are reflective/indicative of ability and performance (even RBI). They are all necessary supplements to good scouting and they are great for fans who can't possibly watch 30 teams regularly. As for this question as to OPS being "imperfect", I am not sure what you mean by "perfection". It is a nice little tool that is easy to use-- add 2 numbers. You don't even need it to be listed to figure it out. If you start including multipliers, it is not such an easy tool to use.