A lot of noise has been made about the difficulty and imbalance of Champions Online. Powers have been changed, builds nerfed, and retcons (respecs) given. But I've been rocking the same, basic build since the get-go.
My build is quite simple. Aside from the energy builder, the three main powers I use are Force Shield, Regeneration, and Pyre. I have maxed out my advantages in each of these skills, including the Force Sheath upgrade to the shield, which allows for protection and energy regeneration even after you've let go of block. For single target dps, I use Laser Sword with the upgrade that increases all damage dealt to targets struck by the sword for a period of time. My other, less used powers are Concussor Beam, Micro Munitions, and Resurgence.
I was worried that the latest patch, which reduced the potency of Pyre's DoT effect, would force me to respec, but I've been managing just fine. Mixed groups of yellow or orange henchmen and villains pose little challenge. I've effortlessly soloed every group mission I've encountered thus far -- most of them while they were still of yellow or orange difficulty.
Still, I can understand why people are having trouble. As I stated in a previous post, the open ended customization of Champions Online invites players to create almost any hero they can imagine; while the need to maintain variety inevitably leads to the possibility for both effective and ineffective combinations of these powers. A problem arises when a player's concept for their hero happens to include what the game has deemed an ineffective combination of powers.
The break between purpose and practice is likely what has led to so many complaints. In games like World of Warcraft, characters are customized within certain constraints, players view customization more as optimization, instead of personalization. Players of those games are less likely to say, "I should be just as powerful regardless of what spec I choose."
So in short, the game may be hard if you play the way you want to, but it's easy if you play the way it wants you to.
My biggest complain about the game up until level 25 is the pacing and availability of quests. You practically have to do every quest in the game to level up. Unlike most other MMORPGs, you don't really have the choice of which path to take as you move up the ranks. This means if you were to reroll a new character, you'd have to do every quest over again, without the option of visiting a new zone or trying a new line of quests instead. Hopefully this will improve as more content is pumped into this nascent game.