Well if you don't know what the features of the DMS are you probably want need them - most don't.
DMS is a good chip but for plain game booting - reliability and ease of install EVOevo is right - go the 17 wire DUO.
Very cheap!
Also go by the reseller list on the Omega teams web site as quoted:
www.duomodchip.com
Evolution sells ripped clones of the DUO not originals. hence the price!
modchips.cc is good - they include free shipping and only supply the real thing.