Thought I'd show you guys my spec, I can 1v1 anyone (though other bunker spec people takes a VERY long time to win) I can 1v2 most people and 1v3+ scrubs. Survivability is the key to a good Bunker spec and this one has it in abundance. I can rush into a zerg, drop some CC/AoE and get out without much problem and have been known to escape a 1v7 without dying. So why should you try it? Because it's awesome fun. When playing solo as an ele it's tempting to just log out, staff DPS specs are shite unless you have lots of targets and people supporting you. Which leads me to my next reason to play with this spec. As you can see I've got 30 points in Water. This is for my own survivability but is doubles up with the benefit of being able to heal others too! So if you play like I am, you can go solo and rip people up with D/D OR you can switch a couple of major traits, maybe a skill or 2, use your staff and become a brilliant support ele. Oh and no, vitality is not a good stat to stack as an ele! vitality extends a fight by maybe 5-10 seconds, healing power and toughness allows you to keep the less health constantly topped up.
I'd much rather the ability to strip 2 conditions just switchng to water than a bit faster movement in air tbh. Plus the extra healing is more welcome than crit. Finally, the 25 point trait (2% DPS for every boon) you will have lots of boons as you are constantly switching attunements so the extra 10% DPS or so is better imho than the crit.
I use the cantrips, with traits they are 20% shorter cd and give regen and vigor: Lightning Flash - escape tool but also paired with churning earth = amazing ambush. Mist form - 1v2+ is essential to stomp a downed foe safely. Also good for escaping. Earth armour - short CD for good burst negation. In support I switch earth armour for arcane wave to spread regen. Elite = Elemental - 4 choices gives better situational options. 1v2+ earth gives a tough wall to dart behind to throw people off, whilst against bursty people you can use water to heal or air to stun people who flee (thieves and eles) Fire for pure dps is good against tough nuts to crack.
Also about runes consider using those: 3 of http://wiki.guildwars2.com/wiki/Rune_of_the_Water (can get those from craftin or TP) +75 Healing 15% boon duration and 3 of http://wiki.guildwars2.com/wiki/Rune_of_the_Monk (can get those only from AC 120ea)) another +75 Healing 15% boon duration this gives u overall 150 Healing +30% Boon duration Additionally with 30 arcane you have now 60% boon duration makes everything on u last for much more time.
http://en.gw2skills.net/editor/?fEAQJAoYhMmYbyx5gjDAEFm8y4hIbQSRxM4A;ToAg2Croay0koJbTumkNNEZuA This is the build i used before using a mix on condi and heal gear, can't make up my mind which i like better Also you tried using V instead of III trait on the earth tree? idk those trigger at *% health shields seem quite buggy