Here is my issue...
Why have a melee character with STR at all?
With the Rapier rules you can have a d8 melee weapon AND cover your AC with the same stat. You can "dump stat" your STR (or at least minimize it for heavy armour use) and still get your full melee bonus'. The long sword has become...
This is a really interesting thought process but it all seems rather unnecessary, from both sides.
There are a lot of spells that are now concentration spells that don't need to be (non-threat, utility spells...like light and mage hand). There are also a lot of spells that the rule works well...