I think it depends on the benchmark you are measuring by.
Compared to 90% of pug-land, the DPS can rock.
Compared to elite DPS builds and players... not so much.
Mine is a Paladin 15, Monk 3, Fighter 2 (Phoenix Champion mark 2) and my DPS depends a bit on how I fight. No crit the best means are unarmed with TOD rings and the shock glove etc... For a crittable foe, I tend to summon a Holy Sword Kopesh (ok two of them) throw on the demon queen armor (for the seeker), and rely on big old smites to crank up the DPS (I can hit 500s on a smite crit).
Most of the time I use a pair of greensteel longswords because I carry some of my amp there, so its my "maximum healing" stance. DPS is decent, but not spectacular. I tend to be #2-4 in full raids in kills, but sometimes #1, just depends on luck. But my guild isn't usually heavy with balls out DPS builds.
I get asked to hate tank from time to time although usually when someone more specialized is not around. The smites are good for pulling initial agro.
Certainly pure dark monks should be a pretty solid notch above a phoenix build so long as TOD is available. My paladin tricks (and low elemental strikes) are about a match for the higher elemental strikes and my buffs a decent counter for higher base unarmed damage. But I have nothing to match Death Touch.
I class Phoenix builds as "Skirmishers" they are about survivability but their DPS certainly is appreciated in a party, even if its not wowing anyone.
I think the Phoenix shines brightest when pugging. It really doesn't matter how good the group is since you are almost utterly independent and self sufficient. It may take me longer to beat down a monster, but I'm likely to finish the fight with more health than I started with having not spent a single mana point or used a single consumable.
Not quite unkillable, but sometimes you feel that way.