The problem with paladin, and gladiator to be honest, is that it artificially limits the entire party owing to its tiny threat generation capacity relative to warrior. Many times in this thread something like "its not hard to slow down on dd" or "well the dd/healer should just manage their threat" or "tanks job is to generate as much threat as possible, and it doesn't matter that the dds can generate more" has been said... and all of this betrays a fundamental misunderstanding of the tanks job. This sort of thing has been said by people with the mentality of "we have 30 minutes to kill ifrit, any amount of enmity will allow the DDs to get him dead by then." There are several things wrong with this.
A) The longer the fight, the more likely something will go seriously wrong. End of the day, a longer fight means more cracks, more cracks means more people will eventually blow up (even if you are 99.9% consistent at dodging, if you have to dodge enough, you will blow). Too many people blow up and you fail. If the fight was say, 10 minutes shorter (very possible), its substantially less likely that things will go wrong. More emnity = shorter fight = smaller chance for mess up.
B) Drop rates aren't 100%. This may seem obvious and off topic, but think about it. We don't (usually) just fight ifrit once in a vacuum. We form groups expecting to kill him multiple times. Faster kills = more kills = more loot. If my group can kill him in 7 minutes and 30 seconds and yours is taking 20 minutes because the DDs in your group are fettered by lower tank threat, then my group is way better off. This is just as true for Cutter's Cry as it is ifrit. More tank hate = higher dps = more loot.
C) As it happens, there isn't plenty of time to get it done. Speed chest on CC requires high out put for the entire dungeon. This means that your DDs need to be able to go full throttle almost the entire time. So when we get to ChimChim and I'm on warrior and putting up way more threat than you on gld/pld, my group is better off. The same DDs in a group with war kill it faster than a group with gld/pld.
D) And, to me, this is most important. A tanks job is not to maximize group dps potential, its to get out of the way. Idealy, the tank should be putting up more threat than the DDs can match going full-boar. A great tank is a tank that places no limits on the group. In a sense, our job is much less "stay alive" and much more "hold threat." We have whm/cnj brd (support class!) to keep us alive. Yes, we ought to have tools to help out, and you ought to use them, but they are secondary to holding threat. By that, I mean, just as a dead DD can't DD, a dead tank can't hold hate.
With these things in mind, lets compare glad and plad. As has been discussed to death already, the two are next to equal in terms of keeping themselves up, perhaps (and I believe it to be so) with gld getting the edge owing to renewable mp and a faster cast time along with feather foot and second wind. As I have said, survivability, however, is somewhat subordinate to threat generation (again, just to be clear, survivability only matters inso far as it allows you to continue building threat.)
Threat generation, some people seem to think pld actually has an advantage over gld owing to spirits within, which i must say is totally lol. Think about the start of a fight, and lets stick with ChimChim. I'm a paladin, so I look at him real hard.... and flash /voke him. And then i position him. And then I stab him until I have tp and hope a dd hasn't pulled it off in those first 30ish seconds. Then I blow boon to drum phalanx spirits. Honestly, DDs pretty much have to just twiddle their thumbs this entire time. Holy succor is unlikely to be used here, I'm moving, I probably have stone skin and regen up, so I'm not even going to take much damage to try to heal, and oh, they took away our PRIMARY initial threat generation tool: over cureing for hate.
Now I'm a gladiator. I get my war face on, I stare at ChimChim.... and I pop invigorate and keen flurry. Why? Because by the time I have him positioned, I can IMMEDIATELY use wardrum, which will also be on a much shorter cool down, and will continue to be used nearly twice as often throughout the entire fight, which is WAY better than spirits within. Not to mention all the extra combos invig will give me across a fight, or shield bashes, or, well, anything I want to use that TP for.
Setting aside the MP issues, curing for threat simply isn't viable. People have said, "well, just cure the dd when it pulls." Yeah, that gets you all kinds of really really dead on ChimChim once he starts voice of the lion'ing the entire group. Not an option. No one but you, other than maybe on chorus and ants, is going to take damage. And you have two whm's with regen and fingers on the button staring at you with faster to cast cures. Good luck with getting a full effect holy succor off, unless your intentionally getting hit by his abilities, which is super scary since your hp is only marginally bigger than that of a wet noodle. The key to fixing gld/pld is actually rather simple: bring back over cure for threat. If we are willing to spend the mp on it, we should get the effect. As it is now, we frequently spend that precious pld mp only to cure for 0. And its just silly to tell the whm's not to cure, its kind of why they are there, and you really can't risk the tank going down.
Prior to this patch, gld and med were pretty close in single target threat. For speed kills, MRD's vastly superior dps probably still made it the better tank, but hate wise I was untouchable on Ifrit as gld. Double and triple melded BLMS couldn't pull him off me if they started casting the moment they were in position, a big part of that was the fact that at any time, if my abilities were on cool down, I could just cure someone/something and get a full 400+ points of healing threat. During jumps I could AOE cure the DDs and get a few k threat, right at the start I could do it on the full party to get essentially a second rampart. If paladin could, at will, drop a 1.1k holy succor on itself for threat, this entire thread would be "hey, pld needs mp" "yeah, i agree" "maybe a bard?" "idk i want to play solo right now" /thread. Paladin's biggest problem isn't that its mp is difficult to manage, but rather that its MP, in endgame, is useless. Paladin is supposed to be a better tank than GLD because its supposed to have all the tanking tools as GLD and then some, when in reality it has less tools + some largely useless ones. Divine Veil on ChimCHim? 100% Useless. Holy succor on ChimChim? 85% useless. Cover on ChimChim -1337% useless. Even hallowed ground is a good 70-90% useless because it fades on movement, and haha, the entire ChimChim fight is moving to avoid abilities. In a short fight, paladin has less threat. In a long fight, it has less threat and less survivability (my gld will almost never run out of mp with feather foot and well used SR).
Temporary solution? Go warrior. AOE Hate grab on the same 30 second cool down as flash, hits for more threat, and it is also a rather kick ass DD (recently came in first place on an 8 minute ifrit kill, as the tank.) Oh, and you never perma-run out of TP. Oh, and the bard is still useful, cus he can Paeon you. Paladin is supposed to be a tank and only a tank, its a job, it should do one thing and do it really really well. Its shiny new thing is MP, that MP should help it tank. It's not a "utility healer" or a "shinier white mage." It is a tank. Make its MP help it tank.
Please note, I love the idea and even feel of paladin's play style. But I can't justify using it when I'm having to say "guiz don't pew pew yet cus I can't build more threat" when I should just be on warrior. Also, Buff PLD don't nerf War, war does what its supposed too, pld is like cake, it is a lie.