The difference is not huge?
How are you connecting your Mojo to the iPhone 6s? If it is going into the headphone jack then I believe you are using the Mojo strictly as a headphone amplifier and bypassing its DAC capabilities. You are then relying on the DAC of the iPhone 6s to do the digital/analogue conversion. In this case I would speculate you are missing out on a significant performance boost which the Mojo could bring to the table.
I don't actually agree completely here. Yes, better compliments/parts/design will sound better than lesser designs. But, in the same design, more power can tighten up bass and add other improvements sonically that are not just playing louder. In this specific case, I have always found the MicroZOTL2 better than the LC (which is a good amp, BTW). It is more clear, open, better detail, tighter bass, better imaging and Soundstage. The LC had more power, though. My initial impression (before kazillion hour burn in) was that the LC with the Elear has more/stronger bass, more impact. I'm also now going to try an upgraded LPS for the ZOTL, see what happens. It coupons be done idiosyncratic synergy. The ZOTL delivered 1 watt, which is plenty for most applications, but I understand the LC delivered more.
Just sayin'