Im currently going with Arboreal (started yesterday up to 24 this morning) It gives you a controlable pet. That helps for diggin in at a camp when solo because you can place your cluster of fnf turrets just outside of range of the spawns. This is essential for sustaining the shroom pile because you need to be able to bow out of combat every now and again to get your power pool filled back up. Having the controlable ranged pet allows you to pull targets one at a time into range and they get melted much faster when they can focus on single pulls.
noob here: don't all speclines have a controllable ranged pet? They definitely all have a controlled pet, and i would think they gave all stationary immovable pet a pull ability
creeping lowers the cost of forest hearts, and the controlled pet will snare from range. By far the best solo spec. Spam hearts and use pet snare to slow mob down as it comes toward them.
Verdant has a tank pet with a short range. PBAOE and abs buff is great for a group setting with mass pulls.. problem is solo you have to heal and use power for dmg.
Arboreal is more of the pvp spec. Aoe, single target nukes and a pet with ok range attack.
At 50 for farming a creep/verd split spec is fantastic!