Berserkers are one of the top DPS classes in EverQuest. In parses of equally geared classes, they will often switch ranks with Wizards and Rogues depending on the type of battle. They are chain-wearers, and share an HP table with paladins and shadowknights, and thus can also often tank in XP groups with sufficient gear and AAs. (For every 1 stamina a berserker gets, they get the same HP gain as a paladin or SK would.)
Berserkers have relatively little utility, but do have a useful instant-cast snare and an instant-cast stun which aids in their survivability. Both abilities check against physical avoidance instead of a regular magical resist and thus land relatively consistently. They also receive a progressive tome line (short duration, long reuse timer) called "War Cry" that buffs his/her group's attack and provides a form of overhaste called "Hundred Hands". Since their addition to the class listing with the Gates of Discord expansion, Berserkers have been touted a pure-damage dealers with all of their other abilities following very far behind in relative importance.
The Berserker class is the 16th and thus far final class to be added to Everquest. Its addition was, in some opinions, a simple ploy to get people to buy the Gates of Discord expansion-- and to some extent, it's understandable why such an opinion exists.
Keeping in line with the lore of the Everquest Berserker, the class was essentially a warrior that could wield only 2-handed weapons and wear chain armor. The damage dealing abilities weren't otherwise to different from their cousin class. However, with much lobbying from the Berserker community, the Berserker class finally received a class-specific set of AAs which enhanced their damage dealing abilities and subsequently greatly separated their DPS from that of Warriors-- nearing Rogue damage abilities.
After the addition of new AAs and with the discovery of the Berserker Epic 2.0, the Berserker became a highly valued member of groups and raids alike. With further AA and ability additions, the Berserker became a "must have" for a raid's DPS group.
There was a very common feeling in the Everquest community that Norrath didn't need another DPS class when addition of Berserkers were announced. Moreover, since there were so few Berserkers relative to other classes on the servers, some posts stated that their arguable gradual overpowering was another attempt to get more people to play the class.
There haven't been many notable "nerfs" to the Berserker class. Some assert, and to a certain extent the developers have confirmed the assertion, that the progression of 2-handed weapon ratios had been held back due to the Berserkers' ability to exploit each gain in efficiency. This suspicion was finally confirmed with what is now known as the "Flurry Nerf/Fix" that went live with a patch following the Secrets of Faydwer expansion. Apparently, one of the AA lines that increased the chances of delivering a "Flurry Attack" was disproportionately high and that allowed for Berserkers over a 90% chance of executing a Flurry Attack on each successful Triple Attack. The "fix" dropped Berserker swings about 10% in standard group situations. The effect on Berserker DPS was great and it wasn't until the Berserker reached level 80 and purchased the newest AAs from Secrets of Faydwer that his/her DPS approached that of the Berserker pre-Nerf/Fix.