Really? ...
Do you have the links to the faster ones?
The groundwork was laid a long time ago.
https://github.com/Telariust/VanitySearch-bitcrackFaster, with multi gpu support. Take existing code and make the tweaks one wants/needs. Much easier to understand and tweak vs bitcrack, IMO. Pool operator can verify that it is faster as well. It also supports the newer cards, 30xx series.