I would like to address several issues brought here:
1. The enchant. I can't claim that I have perfect knowledge of in-game mechanics, so I'm not sure if Spellsurge is working as intended, however since haste paladin to get higher healing output, has to sacrifice some Intellect, mana managment becomes important, so it's rather clear that he will go for something that restores mana instead of 63 SP or 30 Int no matter if at the end of the fight it restores 5k or 20k and I guarantee that not everyone is aware it restores more than it should if what you say is true. However if it's indeed true and Devs confirm that using Spellsurge is considered exploiting due to some bug existing in the code, I guarantee you that those from TFK who have it, will get rid of it.
2. Putting aside all the answers author of this topic got - the whole discussion turned into Intellect Paladin vs Haste Paladin. Lay says that Haste is superior in healing output to Intellect Paladins, simply due to the fact that in the same time it will take Int Paladin to cast 5 Holy Lights, Haste will cast 6 HLs, so even if Int heals for 3k-4k more per cast, Haste will still be ahead by a lot, which is vital on fights where tank takes dmg equal to 60% of their hp. Moreover on fights like Halion, where flames are bugged and their spreading is so different from their retail equivalent faster casting is very important. Here is a proof of how flames should work and we all know how they work now:
1. Proof nr 1 (Paragon Kill) they still resemble the X shape even if slightly off
2. Proof nr 2 (TankSpot Guide Kill) their curling is nowhere near as extreme as it is on Warmane
So obviously people will get hit by the flames, once or twice if they are fast enough and that's where the other difference in healing by Haste and Int Paladins shows - you can get them to full hp, before the tick kills them most of the time, while the slower casting paladin will fail in some cases. And I'm not talking about picking them up with Holy Shock and Instant FoL, because that can be on cooldown if you used it on someone already moments ago and the other might not proc or simply 2 heals won't be enough if more people got hit.
3. The Innervates. While I agree that self-reliance is nice and all, keep in mind that it's a game you play with a group of people, so you all depend on each other and druids have Innervates for a reason. I've seen Intellect Paladins both good and bad call for Innervates during LK fight and even if it wasn't often, they did it, because it's available. Not only that but I've seen tanks drop dead simply, because Intellect Paladin had such slow cast time that LK manged to kill the tank in-between casts. And on the other hand there is Haste Paladin, who while has to manage his mana more efficiently, doesn't have problems with tanks dropping dead and counters the mana issue by asking for Innervate between CD+Plea uses.
So to conclude:
1. Int Paladin wins in terms of self-reliance.
2. Haste Paladin wins in terms of healing output.
We've had many Intellect Paladins join TFK, however we've been proved time and time again why most of our main holy paladins roll haste. Sure you can counter this, by saying that if Resto Shammy or Rdudu helps Hpala, by healing the tank the problem is solved, but why have a situation when one of your healers needs help in the first place?