Tested all three because our team kept arguing about which one sucks least for our React/Node.js stack. Here's what actually happened in production, not some bullshit benchmark paradise.
Claude 4: Fast but Expensive as Hell
Claude helped us find a memory leak that had been haunting production for months. It correctly identified that we were holding references to DOM elements in our useEffect cleanup, something our entire team missed during code review. That alone probably saved us two weeks of debugging.
But fuck me, the costs. Extended thinking kicks in without warning and turns a $5 debugging session into a $50+ nightmare. One minute you're asking it to check a React component for obvious bugs, next it's "thinking deeply" for 18 minutes about software architecture patterns and burning tokens faster than my startup's runway.
The rate limiting during US business hours is genuinely frustrating. Right when you need help most (usually when something's on fire), Claude decides to throttle you. I've been rate-limited while trying to debug production issues, which is about as useful as a screen door on a submarine.
Real example: Had this random window error in our Next.js 14.x app that took forever to figure out - ReferenceError: window is not defined during SSR. Claude caught it was our Google Analytics trying to access window on the server:
if (typeof window !== 'undefined') {
// client-side only code
}
Fixed in like 3 minutes with Claude vs the 4 hours I spent last month Googling "Next.js window undefined SSR" and scrolling through Stack Overflow posts from 2019 that didn't help.
Gemini Pro 2.5: Slow but Thorough
Gemini can process our entire Next.js project at once, which is actually useful when refactoring across multiple files. I uploaded our whole src/ directory (like 200-something files) and asked it to identify where we were violating our own coding standards. It found a bunch of instances - maybe 40-50 - of direct DOM manipulation that should have been using refs.
The 2M context window sounds impressive until you realize responses take like 3-5 minutes for anything complex. I literally go get coffee while waiting for analysis. The context caching helps, but only works maybe 60% of the time from what I've seen.
The safety filters are overly aggressive and randomly flag perfectly normal React code as "potentially unsafe." I've had it refuse to process a simple useState hook because it detected "state manipulation patterns" that could be "problematic."
Real pain point: Gemini flags our authentication logic as suspicious every time. This is standard JWT handling, nothing exotic:
const token = localStorage.getItem('jwt');
if (token && !isExpired(token)) {
setUser(decode(token));
}
Apparently this is "potentially risky credential handling" according to Gemini's safety filters.
Llama 3.1 405B: "Free" If You Hate Money Differently
Self-hosting Llama is "free" like a Ferrari is free after you buy it. We tried running it on AWS and burned through $31,249 in our first month - mostly because I didn't realize p4d.24xlarge instances cost $32.77/hour each and we needed eight of them. Our CTO called me into his office with a printout of the AWS bill. That was a fun conversation. Suddenly Claude's token pricing looked downright reasonable.
That said, when it works, it's actually pretty good at understanding our legacy PHP codebase that the other models struggle with. Llama seems better at older, more established languages and patterns.
The community tools are garbage half the time. The VS Code extension crashes when you need it most, no official support when things go sideways. Just you, Stack Overflow, and a bunch of forum posts from other people equally fucked.
Infrastructure reality: We tried RunPod to save cash. Setup took our DevOps guy Jake three full days, and it still randomly dies when GPU instances get reclaimed. Last Tuesday our entire Llama cluster went down during a client demo - turns out RunPod reclaimed our spot instances with 30 seconds notice. Jake spent the rest of the week drinking.
The Reality Check: What Actually Works in Production
After burning through way too much money and debugging these models at 3am, here's what I'd actually recommend:
If shit's broken in production: Claude 4, but watch those costs or you're fucked. Set billing alerts at $200/month unless you enjoy panic attacks when checking the bill. Great for React hooks and memory leaks, just don't ask open-ended architecture questions unless you want to fund Anthropic's next round.
If you're refactoring huge codebases: Gemini Pro 2.5, but batch your shit because waiting 5 minutes for simple fixes will make you lose your mind. The massive context window is useful for understanding entire projects, when it works.
If you have stupid money and enjoy pain: Self-host Llama, but make sure DevOps likes you first. GPU costs are insane, but if you're already burning $2k+/month on Claude, might actually be cheaper.
For most teams: Start with Claude 4 for debugging and Gemini for large analysis tasks. The combination works better than betting everything on one model. Use Claude when something's broken and you need fast answers. Use Gemini when you have time to wait and need to understand how everything fits together.
None of these will replace a senior developer who actually understands your domain, but they're genuinely useful for catching the stupid bugs that waste half your day. The key is understanding what each one is good at and not trying to force them into use cases where they suck.