Originally Posted by Yitzi
As I said to Ziegander, it indeed would do nothing by itself. But when combined with the change to inherent bonuses (which turns them into an actual increase to an ability score), it does provide a much-needed cap on those.
Suppose a hypothetical human wizard. He takes 20 levels in wizard, which you wouldn't expect due to his Int and PrC's being better, but that's a different discussion. Wizard 20. Starts with 18 Int. Stat increase at 4, 8, 12, 16, 20. Int is now 23. Under the normal system, he can also read a book of +5 Int and get 28 Int. He can also age to middle aged or old if he really wants more Int. Under your system, he is stuck at 23 base int. The difference between 23 Int and 28 Int is a few plusses in skills you can already do easily by level 20, and a 3rd, 4th, and 5th level spell per day. Add in the +6 item we would expect and we are comparing 29 to 34 Int. This is an extra 6th, 7th, and 8th level spell per day. Significant? Somewhat. Is it worth making a new rule over? I disagree with you here: I don't think it is. Inherent bonuses help high level PCs be more distinct from lower level ones. Even the humble fighter appreciates another +2-3 to hit and +2-4 damage which he could get from a Manual of Gainful Exercise.