A couple things before I really get started in on this;
1.) This is my first post on this forii, I had linked here from wotc, and was intrigued enough to join the discussion, so If I say something that has already been noted here, I apologize, I didn't take the time to read 14 pages of posts.
2.) I fundamentally disagree with some of the placements of the core classes, as I typically will go with the: Core Classes are generally stronger than non-core, unless it is broken, like an archivist...
I will completely and utterly agree with the fact that a campaign is very difficult to run as a DM if you have 1 or 2 players who are very good at making optimized characters, and you have 1 or 2 players who are playing half-plate bow using rangers, or spiked chain wielding monks.
I sometimes wince at some of the things I see... and I feel like I must play something broken in order to maintain at least a semblence of ability to make it through a day of adventuring without at least one party member dying.
/Rant
For an example, my current campaign is 5 party members, between 11th and 13th level (including me). A ranger, who is a bow user, but I don't even know if he took the bow weapon style. A monk who wields a spike chain, and is built to trip, but has a strength of 12. A rogue with 2 ranks in UMD/multiclassing into Shadowdancer, A cleric who is actually managing good party buffs spells, and decent melee capability. And my own character, a well-optimized Warlock. I clean house in combat. while most of the other party members struggle to hit or do damage, whether it's not overcoming damage reduction, or bypassing it, or not being able to hit armor class, they fail. The cleric helps them reach adequate levels with his buff spells. I do fine on my own. I chain acid blasts, I dimension door all over the place, I have dexterity coming out the wazoo... I have to purposely play gimped characters from the get go so I don't break a campaign by playing... god forbid... a sorcerer... Warlocks can break a campaign in my opinion... Those vampires that were giving the rest of our party a ton of trouble... It took me 10 minutes to dismantle a freaking covenant... And my DM is just as good at optimizing as I am, except he suffers from either building to my level or dumbing down to the rest of the party. Sometimes I feel like I just need to play whatever concept someone is trying to go for, just to show how it's really done. I love to roleplay... but there is no fun in roleplaying if your character is getting slaughtered at every turn. It gets old. It was fun the first couple of times to play Kenny... but it doesn't last.... I'd rather be Riddick, Neo, John McClain, Gandalf, Dumbledore, Skywalker... etc...
End Rant/
Edit: also, lemme ask a question. "Bite of the X" (SpC) shares with animal companions?, because if so, it breaks a lot of campaigns at 9th level..
I've only recently got into playing druids, out of trying to find something else to play other than generic mind-control wizard/enchanter (By far my all time favorite class)
Human Druid 12
Mounted Combat
Ride by Attack
Spirited Charge
Extend Spell
Track
Natural Spell (Which I rarely even use...)
Wake up in the morning and cast Superior Resistance, Greater Magic Fang (claws), Extended Spider climb (City of the Spider Queen).
First round of combat is Rapid cast (Circlet of Rapid Casting) Silvered Claws (or some other DR negating spell), and Bite of the werebear, both shared with animal companion, pounce/rake/grapple. Second round is 8 attacks between myself and the animal companion with average attack bonus of 20, average damage of 20, overcoming damage most types of damage reduction. And this was what I came up with when I was specifically trying to AVOID breaking the campaign with wildshape or fire seeds...