If you meant that there exists a set of optimizations which can be done using Sepples by the programmer which cannot be done in other languages, well that's not true for a large set of other languages in the real world (any language (implementation) which gives you an escape hatch to machine code means you can make all the same optimizations, and really who is doing the optimization? you're just tricking (instead of asking) the compiler into giving you the machine code you want be restructuring your program, and that's not very clever (if you've already broken that barrier of abstraction, dont be in denial, write that part of your program in the langauge of the machine)).