Do you mean Claude Code? If so, that's what I use(d) primarily for development, and Claude Desktop for general chats. My issue with Opus was that, every time I start a new task in Plan mode, it'd use 50k - 100k tokens and that'd by about 20% of the session limit. A bit of back and forth and its done for most of the work day. Just not feasible at all. The tasks I wanted it to perform were fairly small and contained, "Look at these three files @@@ and add xxx to @file. DON'T read any other files. If you need more context, ask me.". That worked sometimes but not always, still burned a lot of tokens.