When comparing sh vs mksh (MirBSD Korn Shell), the Slant community recommends sh for most people. In the question“What are the best Bash replacements?” sh is ranked 8th while mksh (MirBSD Korn Shell) is ranked 10th. The most important reason people chose sh is:
It may not be the best if you want power, but if you want to write a POSIX script that will run everywhere, it's a pretty good choice.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Truely the most broadly available shell
It may not be the best if you want power, but if you want to write a POSIX script that will run everywhere, it's a pretty good choice.
Pro Most influential Unix shell alongside csh
Bourne shell introduced features such as piping, here documents, command substitution, variables, control structures for condition-testing and looping and filename wildcarding.
Pro Very fast
mksh is very light on resources it needs to use and as a result it's quite fast. It also gets better results consistently than other alternatives when comparing benchmarks.
Cons
Con Not suitable for interactive use
The Bourne shell has always been criticized (most notably by Bill Joy, author of csh) as being unfriendly for interactive use.
It has no tilde (~) expansion. Limited file test operators. Limited math operators.
Con Development is pretty slow
Mksh is part of MirBSD which is barely even being developed anymore nowadays.