Ok, my Reaver is level 33. Brief thoughts:
-Really fun class. Lots of ways to play with a relatively limited weapon choice (used to playing Guardian) and all of its weapon skills are really cool, especially the off-hand axe's teleport attack. Staff looks badass when you use it but it only has two real offensive skills... a shame, but not a bad weapon by any means.
-Went Dwarf/Assassin. Dwarf is... interesting, Assassin has two teleports and an overdrive-like move that speeds you up. I have to say I'm not too too impressed with these skills, although the ethereal dwarf road skill is neat. I haven't unlocked the max level skill of either path.
-They have a great aesthetic. Love the black ink effect in their moves.
Overall, I have a 54 Guardian and this 33 Reaver... and I'm not sure which to go with. Reaver is a super unique class, kind of like an assassin-type but not really, less so than you'd expect from looking at it. I'm not sure I understand the power percentage associated with each stance yet.