I've read no good stories about Haswell for desktop, overclock is a shame and energy saver is near to useless on an overclocked system. I don't know if you want to upgrade the system in future but if u think to stack with this component for some year i'll suggest you ivy-bridge i5 or sandy-bridge too.
i owned 2500k and 3570k too, with overclock sandy beats ivy for a slightly and if u find it in sale or of second hand you gain a special deal
In the other hand u must consider socket 1155 is dead then if u want upgrade later go for Haswell but , imho, ignore K series and go for normal one, you save some money