It occurs to me that the spells of different specialist's wizards should be harder to get rid of than others, say for example a necromancer vs. a summoner and the Enchanter should trump them all and to that end i submit for your thought process this feat.
Persistent Spell
Your spells are harder to dispel
Prerequisite: Greater Spell Focus (Enchantment), 8th-Level Wizard
Benefit: All of your spells gain +1 to their Difficulty Class to resist Dispelling for every 4 caster levels.
It occurs to me that the spells of different specialist's wizards should be harder to get rid of than others, say for example a necromancer vs. a summoner and the Enchanter should trump them all and to that end i submit for your thought process this feat.
Persistent Spell
Your spells are harder to dispelPrerequisite: Greater Spell Focus (Enchantment), 8th-Level Wizard
Benefit: All of your spells gain +1 to their Difficulty Class to resist Dispelling for every 4 caster levels.
Your statement in the first sentence isn't particularly clear, but if I'm reading it right (I have no idea, to be frank), you're saying that you think an Enchanter's enchantment spells should be harder to dispel then a Necromancer's enchantment spells, so you made this feat.
There are several problems with this feat as written, however. Number One: Persistent Spell is already the name of a feat; its a Metamagic Feat found in the Advanced Player's Guide, and its unquestionably better than your feat.
Number Two: Your feat is EXTREMELY poorly worded. It requires Spell Focus (Enchantment) but nowhere in its benefit description does it say that the effects only apply to Enchantment spells. It says "All of your spells," which means ALL of my spells gain that bonus.
Number Three: The feat is extremely weak. It grants you a +1 bonus to your caster level in one incredibly specific circumstance; against dispel attempts made against enchantment effects (I am assuming that this is your Rules as Intended). This means that ONLY when someone is attempting to dispel your enchantment effect does this feat kick in; it is useless at every other moment and it is incredibly passive. You never choose to "use" the feat, it is merely active whenever someone does the specific action. There is a Character Trait that grants you a static +1 bonus to your caster level if your caster level is less than your hit dice. That trait is more powerful than this feat, and a trait is supposed to be worth half a feat.
as to number 3, the + on csster level in that trait is not a comparable benefit since like you said requires you to have more HD, thus be a multi-class caster, which most people agree upon is sub-optimal itself, also the OP says it gives +1 per 4 CL so it does give more benefits than that, at least at higher level
As to the created feat, I would change it to :
Enduring Enchantment
all of your spells of the enchantment school are much harder to dispel
Prerequiste: Spell Focus (enchantment)
Benefit: add 4 to your caster level for the purposes of dispel checks made to dispel your enchantment spells, in addition a creature that is granted a new saving throw against your spells to remove the effect suffers a -2 penalty on this new saving throw.
ok, the name could use some work.. but this is roughly in line with the power level I think the feat should be, there might be similar feats though, so stackability might make it too powerful perhaps.
I think an Enchanter's spells should be harder to dispel then aney other arcane spellcaster's spells, so I made this feat.
Nameing this feat is a pain and all reasonable sugestings are welcome.
It says "All of your spells," which means ALL of my spells gain that bonus not just my enchantment spells. <----- THIS IS INTENDED. It is not porely worded and addresses the power issue.
It grants your spells a +1 bonus to the Difficulty Class to resist Dispelling for every 4 caster levels (your caster level is unaffected)
against dispel attempts made against all of your spell effects.
This means that when someone is attempting to dispel your effect they have a 5% lower chance to do so for each 4 levels you have.
There are no other effects in the RAW that effect this mechanic.