Reply to Audio output on Native Instruments sound cards

Hi all, I have heard that the Audio 10 , S4 and S2 have a louder output than the Audio2, is this true? What about the Z2 is this better again? Is there a difference between the quality of a 1/4" jack plug compared to XLR? S2 and S4 have balanced outs with 1/4 TS while Z2 has balanced outs with XLR. XLR should be better especially over a longer cable, true or fiction?
Cheers, Maxiboy.