PLD is the standard for tank design. Everything feels great, but the single Target needs some work. Something feels a little off to me. Otherwise my only issues:
Enhanced Shelltron: should be a 5 sec duration and made available much earlier in progression. Then give us a 10 second upgrade at higher level to sync up with our CDs. 6 seconds is all kinds of wrong.
Holy Spirit/Atonement is horribly out of wack. HS is hilariously weak now even with Req. It does almost half the damage as Atonement. Its use gets diminished into a ranged skill rather than a DPS increase. Either HS is too weak or RA/Atone is too strong.