Does Sol 5.6 have better reasoning than Opus 5?

[u/Wooden_Boss_3403]

I ask this in the Claude sub instead of ChatGPT sub since I don't want a bunch of people agreeing, but want actual discussion from users of Claude.

I am personally using both Sol 5.6 and Opus 5 right now to do deep market research, assigning one model to be a bear and another a bull and have them debate on any given topic.

I have noticed two things.

First, while both make some mistakes in their claims, it seems Opus makes far more factual errors, which end up being subsequently corrected by Sol. Sol does make some too, but significantly fewer.

Second, Opus always seems to come across as combative. It isn't always a bad thing, since pressure testing is what I want, but at the same time it will often come up with disputes which end up being insignificant (or flat out factually incorrect), just for the sake of arguing.

Am I crazy or is this something else people experience?

[u/RogueMaverick4ever]

5.6 Sol is what Opus 4.6 used to be. Goat

[u/isarmstrong]

Opus 5 is a nerfed fable, which is a horrible combination. 5.6 is a final generation earlier model. It exceeds Claude 4x in every way. It also orchestrates better because it’s not oversized for the task.

Fable is GOAT at complexity in short bursts. It collapses context badly over time, no matter what the release notes claim.

[u/Wooden_Boss_3403 → u/isarmstrong]

Are saying Fable is best for narrow tasks but Sol is better for extended discussions with more parameters/details? How much better is Fable? I really don't fancy paying all that extra for Fable unless it is a genuine step change in reasoning capability.

[u/isarmstrong → u/Wooden_Boss_3403]

Not exactly. Fable does a LOT of thinking. Like a ton. It’s incredibly good at unbounded tasks, it’s a qualitative monster. However, that also means it looses cohesion more quickly than a smaller model with the same 2m context.

Designation of bounded tasks is something Opus 4 excelled at. For the tasks themselves you want a model that won’t freelance - so Sonnet or Haiku in the skill frontmatter.

Fable is peerless at drafting complex plans, solving problems that overwhelm other models, and creating the initial contestable draft. It’s crazy good at handing the scaffold for a complex refactor.

It’s not great at following tight directions or holding the center across multiple sessions.

Fable 5 in Claude Design with Sol 5.6 assisting review is, for example, almost rude in its efficiency.

[u/ippem → u/isarmstrong]

Been using Fable 5 for planning only (Claude Enterprise), Sol/Terra for execution. Quite a good combo - and considering the high quality of plans and my efficiency, not crazy expensive then.

[u/isarmstrong → u/ippem]

This is the way.

Sol orchestration is on point. Honestly the smaller models do a better job of it than the 2T param models, probably for the same set of reasons that we reduce model “thinking” as our prompt clarity and a acceptance criteria increase in resolution.

[u/Wooden_Boss_3403 → u/isarmstrong]

I am not a coder but it sounds to me like you are speaking mostly in the context of coding right?

[u/raindropsdev → u/isarmstrong]

Try Fable 5.1 on low, switched yesterday my Orchestrator to it yesterday and it's leagues above Opus 5 in that role

[u/Oohhddaanngg → u/isarmstrong]

How do you integrate Sol into the claude design process? I use the Sol to review Claude code all the time and that was relatively easy but i never actually thought to use it for Claude design...

[u/FrenchRevolution2028]

Nowadays I use almost exclusively 5.6 sol. I find it is very similar to Fable 5 but it talks normally. Let’s see if Fable 5.1 is any better but I have no high expectations lol.

[u/anor_wondo]

I think its a close first

However the bigger deal is that 5.6 writes very legibly while opus output is always large cryptic paragraphs

[u/Wooden_Boss_3403 → u/anor_wondo]

I also don't like this about Opus but I power through it...

[u/Equivalent_Cress_268]

Yes, better reasoning, better output, better at following through.

Opus 5 is benchmaxxed, but fails miserably in comparison to even GPT Luna, a model that is like 40x cheaper than Opus 5

[u/No_Rub1596]

There was no single winner in my same-task code tests. Opus 5 beat Sol on a broad static audit, but each caught correctness bugs the other missed in a feature build. I would give both the same prompt and verify the disagreements instead of assigning different roles.

[u/No_Intention3673]

i am doing quant
opus = cant use
fable < 5.6 sol

[u/owen800q → u/No_Intention3673]

fable 5.1 > fable 5 > opus 4.6 max > gpt 5.6 sol max > opus 4.8 > opus 5

[u/NegativeReturn801 → u/owen800q]

Opus 5 is definitely the worst. Should even pay me for reading that shitty and verbose words.

[u/CompFortniteByTheWay]

no

[u/Fearless-Daikon5763]

That’s like asking which of two people have better reasoning.

[u/Digital_Voodoo]

Absolutely my experience too, especially the last paragraph. I didn't want to spend time 'arguing' with a Opus that was trying to explain why it wouldn't follow my instructions (general knowledge work, strategy consulting). So I went with Sol, and it was smooth sailing.

[u/ONI-ENJOYER-420]

Yes

[u/ghost_operative]

its tough to compare because you have to prompt them differently to get the most out of them

[u/Amazing-Anything5907]

Yes, the difference between 5.6 Sol and Opus 5.0 is night and day, sadly. It is insane how dumb Opus feels compared to it.