It depends how are you looking at it.
As far as I know, GYSN (str/GYSN) has written a completely new function for generating and replacing key in vBulletin package, which is much more efficient and faster. Also, GYSN code is only obfuscated, not decoded, which improves efficiency as well.
DGT is using the same old system, like SCRiPTMAFiA (R.I.P.).
There is no better or worse. Both work nicely and do the job, so I think this topic is not needed.