As per ndtv review Mach Five is better....any more suggestions
Both the phones seems to be similar to one another. Karbon has 2GB Ram over Micromax 1GB Ram. While Micromax has a 13 MP camera over Karbon 8MP camera. The battery and screen size are similar to each other. You can view the detailed comparison of both these phones here -
http://www.pricejugaad.com/mobiles/Karbonn-Titanium-MachFive-vs-Micromax-Canvas-Xpress-2-55c308b9009c50f30600000a-55b87f1bdd47da25230000b1#!price