i had both dacs but did not compare them directly. considering the relative prices, i bought the ee dac and was not at all impressed with the neko dac.
i'm not criticizing any aspect of the performance of the neko dac, but there was nothing outstanding about it.
the ee dac is very versatile and offers the opportunity to use at least two different 12 volt tubes, namely 12au7 and 12atz. note, the section of the ee dac that useses a tube is a gain stage not a buffer stage. be careful of the gain of the tube you use. i am not sure that a 12ax7 would work as well, as it is a higher gain tube than a 12au7. you might also try a 12ay7.
i had the opportunity to buy the neko dac, reviewed it and sent it back. you can read my review on audiophilia.com.
my system is a bit attenuated in the highs, so i am currently using an rca 12at7.