
lemeres |

?
Typically, you would not go with heavy armor. I think you just went past that one thread that stripped swashbuckler down for parts. I am pretty sure that thread assumed you took an archetype that traded out nimble (once it hits 3, you are better off with a mithral breastplate)
Anyway, I am not entirely sure if precise strike actually helps your damage (it vaguely looks like it just compensates for the difference between a 1 handed attack and 2 handed attack, assuming power attack and decent stats for the level). The only thing that actually adds to your DPR is swashbuckler's weapon training (for the goodness of straight +'s and free improved critical)
The real advantage of precise strike is that it lets you use a shield and still get fairly good DPR. You can go sword and board without going TWF. Between a buckler and mithral breast plate, you can get better AC than just plain fullplate.
And that is why this is a good combo- it can tank and still do good damage. That, and stat synergy with CHA makes for a good gestalt.

Lanitril |
I wasn't aware people think this? The primary advantage of gestalt is the capacity to mix classes in a way where you can cover multiple roles. The Swashbuckler doesn't really add anything except for more damage, and you want utility. Oracle or Bard would make more sense to gestalt with Paladin.
Hmm. I think that might have been more of the original intent, but I personally don't see anything wrong with this. It seems fairly stable. Pump up Charisma crazy high, you have modest casting, and pick up an archetype of Swashbuckler with a gun maybe? Crazy damage, melee or ranged, and some light casting and healing. Honestly, there are more obviously broken builds, but I dunno if it can be written off just for not having full 9th or even 6th level casting.
Paladin on steroids. Not as much steroids and Paladin/Oracle, but I could forgive it for that. Maybe if we knew a little more about the DM's intent and the game?
Edit: I misread. Ahem. Sorry. It's not SUCH a good combination, but it has good damage. Depending on party composition and size, how many roles you fill may or may not actually matter. If you don't necessarily have to fill multiple roles, it's certainly not a bad choice. However, to be quite honest, I think Paladin/Daring Champion might be more powerful in melee, if that's what you're going for.

kestral287 |
Paladin//Daring Champion would probably do better unless there's specifically something Swashbuckler has that you want and DC is missing it. DC offers double level to damage to add on top of Paladin's. Hilarity ensues.
That said, in my experience Arachnofiend is correct. Gestalt can shore up the weaknesses of an individual class very well, but Swashbuckler and Paladin aren't really shoring up weaknesses of each other; simply reinforcing a strength (raw damage).
As a chain of examples, a few of the options I've thrown together:
-Barbarian//Oracle: Oracle shores up several of Barbarian's weaknesses (inbuilt Rage Cycling, good Will save-- and all saves really, Divine Protection is funny-- making Superstition less mandatory, lack of options that aren't "punch it in the face", Cha-to-AC reducing the traditional armor weakness of the Barbarian) as well as reinforcing its strengths (Lunar offers devastating natural attack chains, with Superstition the saves become insane, self-buffing can push damage output even higher, etc.). The ninth level spells of the Oracle are almost gravy here compared to inbuilt class synergy.
-Magus//Swashbuckler: Magus brings its action economy to the table, but its best to-hit boosters depend on a limited resource. Bringing it up to full BAB solves that; piling the Inspired Blade's weapon training on top pushes it even higher as well as adding to damage. Inspired Blade also greatly simplifies feats; Dex to damage is made easy, Precise Strike is free instead of costing arcanas. The Swashbuckler makes the Magus a far more flexible platform by giving it almost the entire standard Magus feat list off the front. Meanwhile, the Swashbuckler benefits from being paired with a sixth-level combat caster and excellent stat synergy.
-Magus//Arcanist: While it retains the Magus' BAB issues, this combination brings full casting to a front-line fighter and the action economy to use both at once. Arcanist brings a suite of abilities to the table, but Wizard could be used in their stead.
If you want a dedicated frontliner, Paladin//Swashbuckler (or DC, ideally) is not bad. But your options will be significantly less than the rest of the party. Consider those three. The one, a heavy frontliner with an arsenal of supporting and healing spells. The next, a full martial (in point of fact one every bit as capable as the Swashbuckler//Paladin) that also has sixth-level casting and a strong action economy. The third, a ninth-level caster with the standard caster weakness-- lack of front-line capability-- completely removed, and the same action economy of the second.
All three are capable of standing on the front lines more or less as well as a Paladin//Swashbuckler, but are much better off of it.

lemeres |

Well, it does shore up defenses to a minor extent. Paladins have fort and will saves, and swashbuckler has reflex. Also, swashbuckler has 4 skill points per level (nothing to write home about, but definitely more than the 2 that paladin has)
But yeah, it mostly just combines lay on hands with parry (which is rather good defensively, I must admit). Besides that, it just 'hits good', which both of those were doing already.
And since we are giving examples of favorite combos- barbarian/ archaeologist bard. The bard archetype trades out performance (which has always been iffy on whether it works with rage) with luck bonuses to saves, skills, and attack/damage, and you can grab a couple dozen rounds of it per day at level 1 (lingering performance effectively triples your daily rounds).
It works well as a combo since bard has spells, skills (large bonuses to perception and disable device, and it keeps that one that lets you juggle a ton of knowledge skills) , and this luck mechanic, while barbarian has fantastic melee, as well as some nice options via rage powers like spell sunder or maneuvers (which seem better, or at least easier for them; I love savage dirty trick for the ability to stagger for a couple of turns)

Mackenzie Kavanaugh |

Reflex is not an especially important save, and there are plenty of other ways to get Evasion if you're really worried about it. Furthermore, you're a paladin, your saves should be through the roof.
A class that grants you the same good reflex saves, more skill points, more damage, and a lot more versatility would probably be the Investigator. Sure, needing Int for alchemy makes you even more MAD than you already are, but you can always trade that out by taking the Sleuth archetype, which grants luck points based on your Cha, so synergy! While it's less precision damage per attack than you get from Swashbuckler (Unless you use Studied Strike and roll well) it comes with a bonus to hit and can be applied to two-handed melee weapons.