To level or not to level that is the question

I recently got my paladin to level 70, he's still my highest level toon (character) and were it not for the new expansion raising the level cap to 80 he would have been my first max level toon. This past week I spent time in game getting my toons to higher levels. To a certain extent I need to do that with my characters if I want to compete effectively on the battlegrounds. Since battleground instances have a level range of about ten levels ideally I should be the highest level possible in my level bracket, I'm not sure if I will do that for all my toons since it can be time consuming.

I had intitially considered only writing based on my experience with one toon but I think that using several toons might be handy simply for the variety of possible experiences open too me. Also using experiences from a variety of toons could make it easier for me to conceal my identity as a researcher. If I choose to focus exclusively on one toon it becomes about how much time I officially give to that one character which could become onerous and possibly color my experiences.