Pathfinder Paladin is excellent!
I haven't played one yet, but I have a Pally in my KingMaker group and several in my PFS pool of players,
so I can share at least the GM side of the coin.
Smite Evil : I love the PFRPG rework of this power! Despite the
endless debating on the Paizo forums,
I don't think it too powerful and I was NOT in favor of the recent errata-nerf mentioned by Volaran.
The 3.5 SE is a 'Power Attack of Good' to one strike, whereas the PF SE is more of a 'Declaration of Good's Power' on one target.
The change is subtle and the damage IS NOT out of proportion.
Lay on Hands : This granted also saw a retooling in the PF Pally. Instead of a total hp chunk allotted per day,
the PF Pally rolls a 1d6 each laying of hands. Times per day is the same math, .5 level + CHR bonus.
Mercy : This granted adds effects to the Laying on Hands. Starting at 3rd and every three levels thereafter, one Mercy can be added.
Each time a Pally LoH, all additional Mercy effects are received by the target.
Remove Fatigue,
Remove Shaken,
Remove Sickened,
Remove Dazed,
Remove Disease,
Remove Staggered.
At 9th can choose from the following additional Mercies:
Remove Curse,
Remove Fear,
Remove Nauseated,
Neutralize Poison
At 12th:
Remove Blindness,
Remove Deafened,
Remove Paralyzed,
Remove Stunned.
The last notable changes to the class (not already mentioned) are the
Aura Powers granted at 8th, 11th, 14th, 17th and 20th level.
It seems fairly obvious to me that the Paladin is now more attractive to play into higher levels as well as being seriously fun in the earlier stages of development.
None of the Paladins in any of my PF games are unbalanced compared to the other PCs, and if you like this type of personality, you will love playing this version of the classic arch-type!