I submit that it is no worse than Dhrystone or Coremark, and correlates well with those while being a lot less code. It is better than those at being impervious to tricky compiler or library optimisations -- I have seen for example libc string function implementations that unroll a loop processing 32 bit words 5 times, not 4 or 8. Why? Well, Dhrystone just happens to call that function with an 18 byte string. Every time. Ugh.

They all exercise just the CPU core (load/store, arithmetic, branching) and L1 caches or SRAM. Which is not a full-system test, but is valuable information.