OK, the spread for True20 is larger than 4E, but much lower than 3.5E because:
1) No synergy bonuses
2) Magic items emulate feats, so no stacking
3) No infinite amount of bonuses (insight, morale, whatever)
4) More skill points per level, meaning a better chance at having a trained skill
5) A more condensed skill list
True20 also gives characters much more narrative control than 3E because of:
1) Conviction reroll: you reroll your check, but with the following ((d20+mod becomes d10+10+mod).
2) The Skill Monkey class has the possibility to gain +4 to a skill check for a whole scene by spending an Action Point
3) At any time a Hero can take a level of fatigue to gain a +2 to a skill check.
4) A Hero can spend Conviction to emulate a feat for one round, like skill focus or something else
These points allow heroes to shore up weaknesses, or temporarily become Skilly McAwesome for a scene.
True20 does have one advantage over 4E in the manner how it handles powers, something I discovered last night.
The Powers in true20 are handled using a power check, which is basically (3+Level+Ability), the same as skills.
This came in handy because the Adept last night wanted to use Teleport to help the Skill Challenge. I simply had him roll the DC with his Teleport Check, which was basically a maxed out skill.
In regards to last night's skill challenge, I can report the following:
The challenge was for 4 10th level PCs:
Skill Challenge DC 26
The Cathedral is in flames, and you hear those trapped inside calling for your help. The main entrance is blocked by the collapse of the marquee. You must somehow enter and get the people trapped outside.
Get inside (Segment 1)
Once the players have located endangered citizens, they need to get to them. The entrance is Blocked. The crumbling structure has created obstacles to getting in or out.
Primary Skills:
Athletics: Clear the rubble out of the way.
Notice: Find an alternate route.
Diplomacy: Does not count as a success, but allows you to enlist other citizens to help clear the rubble from the blocked path, giving a +2 on the Athletics check.
Roaring Flames. (Segment 2)
The flames leap out at you, threatening to singe you with each step.
Primary Skills:
Automatic Success: You run through the flames, ignoring the danger to yourself. Take +4 Damage, and make DC 15 Reflex save to avoid Catching on Fire
Acrobatics: You leap and twist out the way. If you fail, make a DC 15 Reflex save to avoid Catching on Fire
Notice: You find a way through the flames, towards the trapped people. If you fail, you take a -2 penalty in the next segment.
Knowledge (Nature): You understand how fire works and anticipate it’s movements. Does not count as a success, but grants a +2 to your Notice or Acrobatics rolls.
Special: The smoke and heat are exhausting. Everybody makes a Fort save DC 20. Failure means you take 1 level of fatigue, Failure by 5 or more means you take 2 levels of fatigue.
Rescue (Segment 3)
Now that you’ve come in, it’s time to get out.
Primary Skills:
Athletics: There’s no better way out of this than through sheer effort. You lift the fallen and make your way out.
Notice: You navigate the citizens out to safety easily.
Diplomacy: You are able to coordinate yourself and the those trapped. As a team, you exit safely.
Knowledge (Nature): Knowing how to work within the flames allows you to guide everyone out safely.
Special: The smoke and heat are exhausting. Everybody makes a Fort save DC 20. Failure means you take 1 level of fatigue, Failure by 5 or more means you take 2 levels of fatigue.
Victory: You rescue all 20 people trapped inside the cathedral.
Partial Victory: You only rescue half of them
Failure: They were already dead from smoke inhalation.
First of all, the encounter was awesome
Second, they succeeded completely, but it involved a heavy use of resources (Conviction and Fatigue), to the point that 2 of them passed out at the end of the 2nd segment.

The fire came right after they defeated an attack, so they were already wounded.
Now the challenge was tailor made to their abilities, cause the idea was to showcase them as heroes. If I had thrown a Social challenge at them last night they would have sunk, cause their 2 social characters were not there.
In conclusion, I will run things with the DCs as shown below, and report further results.