@Ben_Cohen that clarity helps. I just have a work in progress algorithm that has shown to outperform all those mentioned in previous points which I thought might be of interest to the community. @saagarjha I have just finished Double and Int64 support in ObjC, so now I can fully focus on the Swift version. While I am working on the Swift version I will run my usually small mountain of data set tests on both Doubles and Int64 to ensure their accuracy and stability (ensure not crashing, not sort stability). Performance for both is so impressive that I now fully believe this can also be used on fixed length strings as well with exceptional performance.
The updated framework is available on GitHub.