It should be 75% of the SQ cause it is already a nice drop in the power output which limits what it can drive. It drops so many other features and options. So, give it only 50% of the SQ as well? Then even at $100 it wouldn't be that good of a deal. If that was the case I would start think about keeping my $100 or using it elsewhere. Us consumers are supposed to fight for the most for our $$$. Hey, just keep giving more away, lol!
The X5 is considered a high end DAP. Power aside, most portable headphone does not need that much power to drive unless you are thinking of carrying things like HE-500 but neither the X5 can drive it, you will still need at least, a E12 to "drive it" majority of us uses IEM as our portable headphone, don't see the need of high power output IMO
As mentioned X5 is a high end DAP, asking for at least 75% of X5 SQ in X1? Why not get the X3 instead xP after all it is a $100 DAP, from what I know, non of the sub-$100 DAP uses such DAC like the X1 do and 24/192 support?
Manufacturers are also fighting for a living xD