It's not the same. Recently Opus 4.5 diagnosed and fixed a bug in the F# compiler for me, for example (https://github.com/dotnet/fsharp/pull/19123). The root cause is pretty subtle and very non-obvious, and of course the critical snippet of the stack trace `at FSharp.Compiler.Symbols.FSharpExprConvert.GetWitnessArgs` has no hits on Google other than my own bug report. I would have been completely lost fixing it.