Am I the only one that thinks that Spell Perfection kinda needs the wording fixed in the case of Pally/Bard and the new Magus? is a character cannot normally cast a 9th level spell, why should he benefit from a spell modified to 9th level? According to Spell Perfection, a maximized Chain Lightning would be allowed, but since the Magus can only cast 6th level spells, i think that the feat should be modified from, "as long as the total modified level of the spell does not use a spell slot above 9th level." to as long as the total modified level of the spell does not use a spell slot above the highest level spell you can cast." Because a Pally can take feats like Silent, Still and Maximize spell then Spell Perfection. Then add the Maximize to something like Fires of Vengeance, or maximize those cure spells!
If the feat was called anything but Spell Perfection, I would agree with you. Also at level 15, without the wording to apply it to additional spells, and requiring feat intensive pre-reqs, its hardly overpowered, even in the case of the paladin or ranger.
4 feats for what you get is pretty meh
best use of spell perfection is usually with quickened metamagic to improve you action economy, although in the case of the magus there's alot of stuff competing for that swift action.
and don't forget a maximized chain lightning is still only a 6th level spell and has that lower DC as a result, not to mention being stopped but a globe of invulnerability.
Personally I always thought Spell Perfection was a great way to Heighten spells while keeping them in lower spell slots but with 9th level DC's :)