Leveling a Paladin 40 - 72 the short and long of it.

40 - 72 you pick up a few more good talent points and the all mighty divine storm. Nothing more to report except what I have come to find out...

What I have learned about my class, while I leveled, help me later?
The short answer is: No. Nothing I could not have figured out in 10 minutes at a practice dummy, little bit of time on a spec blog, short time on developing macros with hit rotations.
The long answer is: There is two sides to every argument. In the case of leveling one side is for leveling as a way to best learn your class on your way to 80. In the case of starting at max level, where questing is not important, the game does not begin until you are 80. What you do at 80 in instances and raids is not what you did while questing. In fact you are going to do everything different at 80. Questing does not make you a better player.

How does killing 10 mobs, collecting 10 boxes, and delivering a letter prepare you for a raid?
The short answer is: It does not.
The long answer is: While questing is a nice source of gold, greens, and exploring the lay of the land. Questing helps in no way prepare you for instances or raids. In fact the only real skill questing teaches you to put the most damage out in the shortest amount of time. This can hurt you in a instance/raid by pulling aggro from the tank and wiping the raid. Blizzard needs to give players the option to start at either 80 or very very close to 80 if you already have an 80 on your account.

The instances/raids will be filled with bads who don't know how to play their class if given the option to start at 80 if you have an 80!
The short answer is: If you are a bad player with another 80 your going to be bad no matter what class you play.
The long answer is: No. How bad a person plays is directly tied to the player and not the class. For example you can get a skilled level 80 mage and give them access to a level 80 warlock. The skilled player will have mastered the warlock in a very short time. Another example is take a bad level 80 warrior and give them access to a level 80 death knight. The bad player is now playing the death knight badly. The learning curve is not directly tied to questing it tied to the player behind the keyboard.

All in all I have been pushing the same 4 buttons when questing. Not really a great way to learn my class now is it? The same holds true for every class I have played to 80. Blizzard recognizes the grind to 80 is boring with the addition of heirloom items with XP bonuses. Not to mention the level cap has only been raised to 85 in the next expansion. Perhaps the option to start at max level may be closer than we think.