For me, I feel that the DX100 sounds much better than the zx1.. when combination with FitEar Parterre.
I am only talking about the sound. The zx1 responds much faster and has far less issues and errors when playing music compared to the DX100.
It is also very portable but I found something lacking which is hard for me to describe. Sorry that my English is not so good..
I havent heard the Parterre, but from what I have read, it sounds less dark compared to the 334.
What compliments the 334, is that the ZX1 is a bright sounding player.
The DX100 is no doubt very good, but for specific 334 pairing I would vote for the ZX1.