I don't really think the berserker is broken at all. I'm playing a dwarven berserker (mountain dwarf for the bonus to strength and con), and he is consistently a huge combat monster. When I hit level 4, I took the Great Weapon Master feat, which made him even more of a beast. Now, at level 5, he just runs into a group of monsters, rages, and goes to town. Reckless attack is very strong; yeah, you get hit a lot, but you're taking half damage from most attacks, and the advantage adds to your accuracy. Think of it as doubling your hit points; not only that, but healing is twice as effective while you are enraged.
If you notice that you are getting swarmed, go frenzy, and you will have 3 attacks at 5th level (more than any other class at this point). Yeah, the exhaustion can be bad, but one or two levels is manageable, and it is up to the player to manage when he goes frenzy to prevent himself from getting too exhausted. They added this feature so that they could prevent the berserker from going frenzy all the time...the player has to make the judgement call on when to go nuts. If I were going to change it (and I wouldn't), I would leave it as is, and only remove the exhaustion effect at higher levels.
Does the berserker have a lot of range outside of combat? Not really...but that's not what this subclass is built around.
tl:dr; Frenzy is not as bad as people think. In practice, the berserker barbarian is a very effective combat monster.
If you notice that you are getting swarmed, go frenzy, and you will have 3 attacks at 5th level (more than any other class at this point). Yeah, the exhaustion can be bad, but one or two levels is manageable, and it is up to the player to manage when he goes frenzy to prevent himself from getting too exhausted. They added this feature so that they could prevent the berserker from going frenzy all the time...the player has to make the judgement call on when to go nuts. If I were going to change it (and I wouldn't), I would leave it as is, and only remove the exhaustion effect at higher levels.
Does the berserker have a lot of range outside of combat? Not really...but that's not what this subclass is built around.
tl:dr; Frenzy is not as bad as people think. In practice, the berserker barbarian is a very effective combat monster.