Check out the Perfect Seal thread at HF; I just posted a comparison of the Deca and Andromeda: http://www.head-fi.org/t/718626/perfect-seal-custom-in-ear-monitors/75#post_12696312 The 1Plus does have a nice bump in upper mids but I'm getting slightly more treble presence and deep bass emphasis over the mids, so it's a very mild V shaped response, much akin to the type of response from the Sony EX1000. The 1Plus is more sparkly up top than the Martian, although the Martian treble is a little more articulate. Martian middle mids are definitely more focused and forward than the 1Plus; Vocals will seem much more intimate. Both have a deep bass focus but the Martian is a little tighter and faster in bass. The 1Plus is a little more bass boosted over the Martian as well. Overall the Martian will sound more reserved than the somewhat rambunctious 1Plus. If you are a guitar driven rock-n-roll listener, it doesn't get much more fun than the 1Plus.