The one included in KR_KT ROM is also included in official 2.2.1, so there is no "stock" and "non-stock" anymore. They're both stock.
One difference I know of is that the newer bootloader enlarges or otherwise takes care of BOOT partition where boot.img is stored, and allows people with bad sector in that partition flashing larger boot.img than the older one.
Although our mobile devices today are capable of executingnearly every task we normally … more
22 Aug 2014
By Will Verduzco
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?