All I Know is I have an Ice/Willpower sentinel that through thoughtful choices in enhancement sets and incarnate abilities can kick some but and act as a halfway decent controller. I actually convinced some people in a tinplex of that fact. A sentinel takes more thinking in leveling up, enhancement slots and sets, and incarnate abilities. With my playing style, my blasters get killed a lot, my sentinels, not so much.
Also, I like to take underpowered characters and try to make something out of them. It keeps the game interesting.