Alright so I decided to play a GWF because I'm a fan of the underdogs. I read on this forum that people are saying they struggled soloing dungeons at 25 on GWF. You sir are nuts. I'm currently level 30 and I've never felt stronger 25-30. That entire area is MADE for GWF. Nothing but weak numerous monsters. I thought I'd shed some light on my GWF experience so hopefully future GWF can get passed this imaginary hill.
Level 1-6 : It's level 1-6. Proceed by face smashing your keyboard
Level 6-18: Pick up your legacy weapon, without this thing these levels would suck. Face smash keyboard until 18.
Level 18-25: These were the toughest in my opinion because bandits can heal. I focus mainly on Armor Pen, Deflection and Power gear. I used Takedown, Recovering Strike and Might Leap as my encounters. As much as I loved the dire wolf pet I decided to take the cleric pet to save on potions. Dying wasn't the problem, the kills were just slow because of the potion drinking bandits. Save takedown until they are using a potion.
Level 25-30: Same spells, use Unstoppable and spam wicked strike on almost every encounter. Easiest levels by far and I definitely feel GWF is getting much stronger from here on. I changed my gear to Crit as I'm mostly using the middle tree on the trait points. I use weapon master and determination as passives.