I Switched From Sol to Opus 5. $20 vs $100. The Difference Is Real.
This post isn't a benchmark comparison. It's a real user with real projects who spent money on both.
Here's what I found.
The cost reality check
Running Opus 5 on Extra reasoning burned through my weekly limit about as fast as Sol on High did on my $100 Codex Pro plan.
Let that sink in. $20 Opus 5. $100 Sol.
That's not a win for Opus on cost efficiency — both burn tokens fast when you're doing serious reasoning. But it means the price gap is doing something real, and you should factor that into which model you're actually paying for.
Planning: Opus wins. It's not close.
For planning, Opus 5 is way more goal-oriented. No fluff. Just a straight, coherent plan and it keeps you involved the whole time you're designing it.
After using Sol since release, my AI workflow and project rules had gotten so complicated I'd basically lost track. I didn't really know where things stood anymore. Opus brought me back into the project. Now I actually know what's going on.
Sol, on the other hand, overengineers everything. It runs in circles. It loses you completely along the way. And unfortunately, it produces code I can barely look at without needing to go breathe some fresh air.
The fair take on Sol
To be clear: Sol is still a genuinely strong model. It's just better as a reviewer than a planner. When I need someone to look at what I've built and give me concrete feedback, Sol is excellent.
The problem is using it as your primary planner. It wants to redesign everything, refactor everything, abstract everything. For a quick review pass, that's useful. For actually deciding what to build next, it sends you in circles.
The communication gap
Opus 5 walks you through its reasoning and stays concrete. It doesn't drift into pseudo language that sounds smart but means nothing.
I kept catching myself typing "ELI5" at Sol after a long answer. Not because I'm dumb — because Sol answers questions nobody asked in language nobody speaks. With Opus, I actually read the whole answer and understood it.
That sounds small. It matters when you're in the middle of a complex build and you need to actually understand what the AI is proposing, not just trust that it sounds confident.
What this means in practice
If you're on the fence: Opus 5 at $20 is giving Sol at $100 a real fight on the things that matter most for actual builds — planning, coherence, code you can actually read.
The cost comparison is closer than the price tags suggest when you factor in reasoning mode burn rates. But on the quality of actual work output, Opus 5 is landing closer to Sol than the marketing would have you believe.
Worth trying if you've been paying for the higher tiers and wondering if you're actually getting your money's worth.