I think it's all about how you play the Repulsor vs the Landraider.
Too many people on forums have advice based on thoughts, or numbers... I prefer playing the game, several times, with the options in question and coming to my own conclusion.
And this particular conversation is one I feel I have a very large amount of experience in-
Over the last 2-3 months I've played a high number of games with Ultramarines, and Black Legion almost exclusively. But by far most of these have been Ultra's.
So I accept this is just my opinion but without sounding harsh... I disagree with a large portion of what's been 'observed' about Landraiders vs Repulsors. I will say again it's just my opinion, and although from experience, it's also heavily meta dependent. In a nutshell:
- Landraider is substantially better in my games.
- I started with dual Repulors. It's an easy to make list for Primaris and it's nothing new to maximize it with Guilliman in the middle. (I haven't used them with Guilliman).
- I then tried dual Landraiders, and settled on a split of Landraider and Repulsor.
- They have to be played differently. The Landraider is best used to protect characters and important units. You really shouldn't move it high in the battle field until late game or to bait people (IE: Leverage a bad charge from your opponent to sling shot your CC squad into a favourable counter charge the following turn.) Otherwise they're too easy to destroy, and kiting cover is a real thing where I am. Anything short of a Castelan can be hidden from to large degree.
- The Repulsor really NEEDS to go forward. Too much of it's fire power demands it. It NEEDED fly because it has 24" guns, and depending on secondaries, a 24" set of las cannons and/or 30" Cawl heavy bolters (various flavours of Onslaught)
- The Repulsor therefore dictates a favoritism towards a medium-to-close support unit inside of it. - You take advantage of fly, and all its weapons get to participate.
- The Landraider conversely favours a long range passenger list. I have had immense success with Centurions in Landraiders (of any type). Some times people ask me why I bother since I don't typically move landraiders a lot until mid game: The reason is really straight forward: I lose turn 1, then people who know my army will do -anything- in their power to annihilate my Centurions. (Yes, they are that big of a threat, but it's not a centurion thread so I'll leave it at that.)
So the goal with a Landraider is; park it, hide passengers, prevent a 'seize' roll from ruining your day, then use the 3" disembark + move to create a strong, mildly mobile base, or start going forward with assault Cents, or whatever your cargo is.) The Landraider has largely done the first half of it's job. VERY different from playing a Repulsor.
- The Landraider having a 2+ save is an incredible difference maker. In all of these games if I told you the amount of Las, or las equivalent type saves I've made on that 5 up save you wouldn't believe me. In the span of the last few months it has convinced me (reluctantly) that this alone makes it a better choice for me over the Repulsor. Keep in mind this is coming from someone who really likes the Primaris aesthetic.
- The Repulsor loadouts have been very long and varied for me. Since you should play it different it should be holding a different type of passenger. Often I sling shot Calgar out of it. And/or an entourage of support characters (prevent sniping). Sometimes these guys support the Centurions with Banners, and Apothecary, LT, etc etc. Sometimes they are meant to very aggressive... using Aggressors. I used to use Helblasters, I just don't like them enough. Centurions put them to shame in my lists. I feel like I have to overcharge them all the time, and rely on banner bonuses/coming back from the dead too much. (I might feel different if I was a Dark Angel player).
That's the second problem with the Repulsor.. it holds units that I don't think work as well. I'd love to put assault Cents in one for example... Aggressors (used in this manner) are horrible... I still despise Power Fists... even if they were free. I hate the -1 to hit.
- One of my strongest lists features one Repulsor and one Landraider. I love it when people pick on the Landraider first... it almost 100% lasts longer. Plus since it's a better backfield producer, it doesn't need fly. And it's cargo reflects that. Plus it works VERY good with certain combo's.... a long range Dread (cheap) dread with Wisdom of Ancients, placed beside a Landraider and hiding a Thunderfirec Cannon? That's a really decent combo that can also heal itself!
Recently to further explore Indomnitus Crusaders I've been using much more Intercessors, and they cost a lot and I'm finding it harder to include dual units like this so I've gone back to the single Landraider over the Repulsor and it just works better... 4 lascannons, 48", and Centurion protection, plus that 2+ save just is a great combo.
Perhaps if I could put something more.. potent in the Repulsor (sorry not going back to multi-Helblaster lists anymore.. yawn.) it would be different.
- Black Legion lists I've used feature a lot of stuff being extremely aggressive, so I can't really leave the Landraider at home. Most games I expect to lose the LR turn one, simply because of the playstyle change... this is a real factor in determining the 'value' of these units in your army... anyway, the Landraider holds Berzerkers loaded up with axes and a Dark Apostle. I use this combo to get heat off my Daemon Princes. The point is the Landraider's 2+ save is just huge here, and again I've had Dark Angels with 3 Damage Helblasters allowing my Landraiders to have at least a 6+ save.... against multiple medium damage shots, that's huge over time (especially with the Thunderfire Priest or Warpsmith nearby).
Again, just my experiences, but right now as similar as the vehicles appear the Landraider significantly outperforms my Repulsors.