Paladin/sorcerer vs paladin/warlock

[Klorox]

Which is better? Why?

[Gastronomie]

Which is better? Why?What sort of question is that?

There's no such thing as a universally better option. What are you aiming for? What is your goal? What sort of character do you want to build?

In my understanding, Paladin/Sorcerers are extremely efficient gish builds that can be both excellent warriors and casters at the same time, and in the same turn as well with Quickened Spell. Their way of fighting is different from a pure Paladin, but at the same time they're also different from a pure Sorcerer. They're just their own thing.

Meanwhile, at least as far as I know, Paladin/Warlocks are "Paladins who improved their smiting with Pact Magic".

These two are absolutely different things. It's like asking which is tastier, a cheeseburger or grilled cheese. Just because they're both meals that involve putting cheese in-between two slices of bread, doesn't mean they're the same thing, or that one can easily compare them.

[djreynolds]

Warlock has some short rest recharge on some spells that goes nicely with your paladin's channel divinity. And a ranged cantrip in eldritch blast that you can shoot at separate targets or push and add your already high charisma modifier to.

Sorcerer is as good, no eldritch blast, but you gain access to the shield spell, which is huge. And you get sorcerer spells.

I find warlocks may want more paladin levels for aura of protection, but may stay mainly warlock as they are focusing on their pact of the blade.

Sorcerer is great right off the bat, 2 levels of paladin and you can smite or use teleport, whatever.

Or you can dip 2 levels of warlock and sorcerer each and get a familiar from either one, and EB and the shield spell.

If your party has a lot fighters, monks, and warlocks who like short rests... go warlock.

If your party doesn't short rest much go sorcerer.

[Citan]

Which is better? Why?
There is no "which is better", each brings different things.
The main benefit of Sorcerer on Paladin is the addition of several spells and Metamagic, many of which synergizes with both Paladin and Sorcerer's spelllists.

The main benefit of Warlock on Paladin is providing strong attack related benefits (best ranged cantrip, CHA-based quarterstaff, magic resistance familiar) as well as short-rest slots which can be used to enforce your preferred tactic every fight (aka either use it to enable Armor of Agathys / Elemental Weapon / Mirror Image / Greater Invisibility / insert other... Or keep it for nova strikes), and strong benefits through invocations (the most sensible for such a multiclass being Ritual Caster imo).

So, it really depends on what you aim for with your concept, both are pretty good choices.
My ideal theorycraft would probably make a mix of the three classes to be honest. :)

[Carlos Barreto]

Not sure if it helps, but I'm currently playing a Fighter 1/Sorcerer 6 (Favored Soul) gish and I'm loving it!

Favored Soul Sorcerer has some level of gish ability (Extra Attack at Sorcerer 6), although it's proficiencies are terrible (that's why Fighter 1). Fighter also gives Constitution proficiency, which is a god-sent feature for a melee gish.

On later levels, I would like to take 2 Paladin levels to Smite my enemies.

So a Paladin/Sorcerer build can give you nova damage against single targets and you will smite better than a pure Paladin, since you're a full caster and will earn greater slot levels much earlier. And as a Sorcerer, you will have access to all those wonderful AoE damage spells.

Finally, I think there's so much synergy between Quickened Spell and Extra Attack. Normally, I Quickened Spell only allows you to cast a normal spell+cantrip. But if you have Extra Attack, you can make two melee attacks (and if you have Great Weapon Master feat, that's even better!) and throw a Fireball or other great spell as a bonus action.

[PeteNutButter]

IMO there is an answer to this question, and that answer is sorcerer. 5e is all about action economy and quicken spell is lack luster on its on since you can normally only back it up with a cantrip, but when you can back it up with a melee cantrip or extra attack depending on class breakdown and smite on each hit...

No other class combo can boast such action economy and nova capabilities, so if that's what you want it's got it. Warlock paladin has its perks, but like most Gish builds it runs into the age old problem of should I attack or cast a spell, only paladin/sorcerer can do both (or any melee/sorcerer/x).

[Spiritchaser]

One thing that might be worth mentioning explicitly is the option of a quickened melee cantrip and then two attacks

This is more of an option for Paladin 11 or 12, dragon sorc 8, because improved divine smite makes the cantrip damage that much better.

With 2 sorcery points to cast, a cantrip may seem a waste, but with green flame blade you get + damage from dragon sorcerer, greatsword damage and improved divine smite on top, damage becomes superior. If you go devotion GWM, vengeance GWM or oathbreaker it becomes very superior. With spell conversion to sorcery points, you can sustain it almost indefinitely.

This build doesn't need to smite much but can, though obviously not as much as 2/18. It plays more like a Paladin that's a bit more magical, and arguably like a Paladin that is better at being a paladin.

I mention greatsword because it makes best use of bonus attack, but really, this works fine as S+B, (or even a stealthy dex build. Edit provided you can make the STR minimum, or, hopefully, that your DM will be flexible about dex instead of str)

Counterpoint: you will always be beset with doubt as to what to level next