Al said:The problem was one that only became apparent using twinked-out characters, prestige classes and feats (GSF). The major issue I have with it is similar to that of dcollins'- the core rules are being rebalanced (underpowered) in order to remedy supplements. The core rules were already balanced, the supplements were not. However, rather than fix the supplements, WotC downgraded the core rules in order to try to bring the supplements into line.
Yep, that's exactly what they did, and it's a really dumb way to try to balance things. They should have never let things get out of hand in the supplements in the first place. There was nothing wrong with the +2 DC from Spell Focus on its own - it was only when you combined it with a bunch of other feats and PrC abilities that it led to astronomically high DCs.
At top-level, therefore, the average person has a 40% chance to save against an average spell. Was it particularly broken to reduce that chance to 30% for one school? If a wizard used a given school half of the time (pretty specialised), and it was a save negates type spell (optimal for SF), then he has increased his offensive capabilities by one-eighth at the cost of a feat.
And don't forget that at top-level, a great many of the opponents a wizard is going to face will have SR. And since SRs seem to be getting an across-the-board boost in 3.5, the odds of a wizard affecting a monster with a spell will be considerably lower than what you listed - especially if Spell Penetration/Greater Spell Penetration get a similar nerf.
My group will probably house rule it back to +2, and I'll definitely do it in any campaign I run. At +1 DC, there's no way I'd ever take the feat unless I needed it to qualify for a PrC or I wanted it for role-playing flavor (the "I'm a master of illusions" type character).