I'm also using it as my daily driver. I've been trying Opus 4.8 this week to see if I was missing something but haven't noticed a meaningful difference.
I'm working on a fairly routine full stack web app that isn't doing anything incredible. Once I had the patterns I wanted in place, it's been very capable of following those with new work. I also don't ever give it long running tasks, it's always focused and small chunks.
My typical work flow is 1. /grill-me feature description 2. Create a plan 3. Manually review plan and tweak as needed (usually very little to none) 4. Build the plan
All with Composer 2.5. Earlier on in the project I used Claude and GPT for #1 and #2.
I find it really hard to justify the other models for the performance/cost I'm getting with Composer 2.5. Maybe it's not as strong as the frontier models, but it's been plenty good enough for my use cases.