I was just the 2nd posts above you, you shouldn't miss me.

Anyway, it's not a good combo. It's a GREAT combo.
However, in the end, it's up to you. I say it's great and so do a couple of 668B users that have the C30/Gumstick, but that doesn't guarantee that you'll like it..

Haven't listened to or even hold a piiq marqii; I can only give some advice based on reviews@looks. Here some points on what it might be if you move to 668B.
- You'll probably feel less comfortable.
- There will be less bass. 668B is a monitoring headphone after all.
- You'll hear more treble, and it'll probably be too bright for those who aren't used to it.
- Other than that, I expect the 668B to be better than piiq marqii.

I was Sony fans before, i have a few Sony cans. Always test Sony with my wife. She not really an audiophiles, but she know how to differentiate between good and bad cans. None of of Sony she really like. But when I bring her to KLAV show and test Superlux for the 1st time, she straight away choose 668B. After some discussion, decide to buy Samson SR840 (Superlux OEM products).

Now we use C30 with Samson, put all Sony in the drawer already (maybe in the dustbin soon).