It depends on workload. It is difficult to quantify the trade offs without knowing that. The problem is in languages like C#/Java almost everything is an alloc

It depends on workload. It is difficult to quantify the trade offs without knowing that. The problem is in languages like C#/Java almost everything is an allocation, so I don't really think reference counting would work well there. I suspect this is the reason PyPy doesn't use reference counting, it is a big slowdown for CPython. Reference counting really only works well in languages with low allocations. Go mostly gets away with a non-compacting mark-sweep collector because it has low level control that allows many things to sit on the stack (like Rust/C/C++, etc.).