Depending on your definition of serious (I'd say it's serious when people pay money for it), I'm doing that and am quite happy with it. I haven't tried building

Depending on your definition of serious (I'd say it's serious when people pay money for it), I'm doing that and am quite happy with it. I haven't tried building any Java code though, only Go and Swift. I'm seeing about 2x performance (eyeballing build times) of a recent Intel MBP for compiling a medium size Go codebase, running natively on arm64. The machine is noticeably faster than previous iterations for most tasks. I've made an effort to avoid emulated code though so am running a patched version of Go 1.16 and tools. Not all tools have officially supported native versions yet, but the performance is definitely there.