That module may have been too easy. 4e itself hasn't gotten too easy. In fact, with updated monster damage values, 4e has gotten harder. A lot harder.
I thought that when the monster damage was updated too, but anecdotal evidence on how optimized Essentials PCs are for damage seems to show otherwise. Course, in our normal game, the may be due to the fact that we have several PCs that can hand out temporary hit points, so the increased monster damage is diluted somewhat for our normal table game.
I have to ask, how effective were those two Controllers? Which Daily was used, and how? A Controller has the ability to, with the right power in the right situation, completely devastate an entire Encounter. I always say: "A Defender's job is to take hits. A Striker's job is to do damage. A Leader's job is to heal and buff. And a Controller's job is to make the DM curse in rage."
Well, we only had one controller in the first encounter. He didn't especially shine in that fight, but he pulled his weight. In the second encounter, the Wizard and Hounds won initiative over the PCs and the Zombies lost initiative to the PCs. So, the Wizard hit 4 of the 5 PCs and immobilizied them and a few PCs went bloodied in round one before they even got to act. But, since the Hounds had melee attacks, immobilizing PCs did very little since the Hounds had to move in to attack. With such a strong first round for the NPCs, the Bard hit the Wizard with Stirring Shout (Daily), and then the one Controller teleported out of the area, hit the Wizard and then used an Action Point to do Burning Hands on the Wizard and the Hounds. The Wizard was a little close, but most of his At Will powers were range 3 or less, so I had him move in behind the Hounds. A potential mistake in hindsight, but he was not close enough for a Close Burst 1, but he was close enough for a Close Blast 5. The second Controller just did Close Burst 1 attacks on the Hounds in round one and the Zombies in round 2. The PCs formed a line in round 2 that allowed two PCs to burst / blast all 3 Zombies (Zombies are stupid, so I just had them rush the nearest PC and not try to specifically avoid bursts/blasts).
The Daily power used was Stirring Shout which gave each PC who hit the Wizard healing of 4. So, it wasn't a particularly strong offensive Daily used, it just helped the Bard keep the party alive for a round. In fact, the Wizard went down so quickly at the start of round two that we joked about how the Thief should have let him live a few more rounds so that the PCs could heal up.
And if things are too easy, always feel free to toss in an extra monster or two, even in mid-combat, if it is at all feasible to do so. Players like a challenge; if things aren't challenging, few will complain if you make things more "fun", in a Dwarf Fortress sense of the word.
When 4 NPCs (including the BBEG) are dead and 2 NPCs are bloodied at the end of round 2, it's kind of pointless to "just throw more foes" at the PCs. It's also something that I rarely do unless there is a good in game justification for it. I allow players to have their successes, even the fast (i.e. few number of rounds) ones. In this case, three of the PCs went bloodied (one down to 2 hit points, one down to 4 hit points), so they were challenged and the dice gods could have knocked two of them unconscious. It was more the number of rounds in which the PCs cleaned clock and how much average damage they did that caught my attention. These encounters were not easy in the sense that the PCs hardly got touched (they got hit fairly hard, especially in the second encounter), it's that they wiped out 2 tough, 2 moderate, and 6 easy foes in 4 rounds in one encounter and 1 tough and 5 moderate foes in 2+ rounds in the second encounter. The speed at which they wiped out the foes is what surprised me.