I'll leave RvR opinions to those more experienced with Valewalkers here, but for PvE, I've found it to be the best Hibernian melee class at soloing, due to its rapid kill speed and fantastic sustain via life drain. Resting can be avoided for a long time with endurance potions (search housing for improved elixir of speed). When grouping, it's capable of matching any other MDPS class and often surpasses them with the Blizzard Blade positional nuke proc. Its only limitation is inadequacy as a tank, for which a shield is wanted.
Your effectiveness will continually increase as you gain new levels of the self absorb, until reaching the last upgrade at 34 with 33% absorb. That combined with the AF buff leave Valewalkers as strong as scale wearers on paper, but slightly weaker due to the AF calculation and lower total HP. There's also Evade IV at 30. So don't expect to remain as squishy as you feel at low levels.
Speaking of levels, use /level at any trainer on this server to immediately reach level 40 with a full selection of equipment. Empty your inventory being doing this. Then group to XP (quickest) or start completing XP item tasks by killing the mobs listed
here and
here (still quick solo). 10 items per task can be turned in. Some groups will also choose camps with these items to level, for additional efficiency.