A quick benchmark comparing performance of writing to a map versus appending to a slice. I also created two separate benchmarks to compare setting bool versus uint8 in the maps. It looks like the map with the uint8 values is the fastest option. Results Mon Dec 17 09:37:28 > go test -bench=. -benchtime=20s goos: darwin goarch: amd64 pkg: github.com/miketmoore/mapsvsslicesperf BenchmarkMapBool-8 100000000 208 ns/op BenchmarkMapUint8-8 200000000 180 ns/op BenchmarkSlice-8 20000000 1967 ns/op PASS ok github.