POSIX shell scripts shebang #!/bin/sh vs #!/usr/bin/env sh, any difference?

I recently noticed that many scripts are using /usr/bin/env in their shebang . I have seen that mainly using Bash and Python , but thus far never in conjunction with POSIX sh (ash, dash,...). I wonder why, and if my, meant-to-be highly portable, POSIX shell scripts might benefit from the env approach? *** Is there a general concensus on whether to use: - standard: #!/bin/sh - environment: #!/usr/bin/env sh *** Let me stress this enough: **I never have seen this with sh.**