I don't care if they are PLD or WAR...as each role has it's pros and cons. I care far more that the tank is not a jerk....or at least knows their own ability/takes into account what the party comp/gear is.

But if with skilled/geared/kind tanks:

Honestly, WAR has more 'OMG cure II spam moments' when I'm WHM...but they also kill things faster, and I've healed WAR's that somehow someway shed damage in ways I wonder where they are putting it.
PLD's have more natural padding, and less 'OMG moments' but things tend to be slower and therefore, MP management can be tighter.

I have played SCH less...but basically, it' the same trends.

I might actually prefer healing Warriors...but that's only because if they can play modestly well, I can heal any damage they take+ DD and things seem to melt more. Also, since we do sometimes play the 'how low can you go' game when I'm stance dancing, it's likely more exciting for me as heals (I still get the tanks commendation typically...so I must not be scaring him too much w/ the stance-dance+ timing heals when he's low)


That said: a badly played PLD is easier to compensate for than a badly played WAR. And many of the 'tanks' you come across via Duty Roulettes aren't actual dedicated tanks...so there's some disparity in the skill. But when you meet a dedicated tank as a dedicated healer, (esp a kind one), it's gonna be awesome.