does it affect performance? I was pretty confident that it was neutral, not very familiar with Shure IEMs.

Get an IfI IEmatch adapter. with that i could plug in my Campfire Audio Polaris V2 into the hip-dac & Fiio MkII without any hiss. Dont need to get a new DAC just to get rid of the hiss

Check the q1 mk2 reviews with HD 6xx, which if I am not wrong are 300ohms. It can drive it at listenable volumes unless it's really inefficient. so i think the q3 should also work fine

Amir had said a while back that the test he does is mostly to see if the values are matching to what the company claims. Measurements are used to tell what are the technical flaws, like an amazing 6Watt 1000$+ Amp which can power 600 ohm headphones without distortion is meaningless to a person...

Both dac/amps can drive it fine. just Loudnes wise it work well at about 60% volume(3 O'clock on the dial) high gain on the fiio q1 and 40%(12 O' clock dial) low gain on ifi Hip Dac. I listen around 70db and 80db loudness at max . Detail in music is still present. Bass has the amazing detail...

Hope this comparison helps. I have both the Fiio Q1 Mark II and ifi HipDac, Ifi hip dac has way more power but this becomes an issue if you have IEMs. Even on low gain High sensitivity IEMs(CA Polaris in this case) get very loud and due to not so great channel balance at low volumes, it becomes...