Always worth leveling PvP characters because that's where the game is fun.
What you're talking about is not an issue of balance, it was an issue of damage.
At some point in pre-open beta, the damage calculation scaled very poorly, with people doing 100k crits to mobs and even sometimes to players when they have +15 weapons.
Also, for a great deal of POB, defense didn't calculate into the damage calculation, so you found DWs one shotting Zombies in papaya with Energy Siege with 8000+ damage.
You're most likely talking about one of those time periods.