Playing with this set some more. Wound up using poweramp's tone control to boost the bass. The drivers are physically capable, perhaps just tuned not to be excessive stock. Anyways, I'm happy now :)

I've owned the s4, s4ii, s215 and now the r6. S4ii were perfect in my mind. 215 was super uncomfortable and sounded worse than s4 to my preference. The new r6 without burn in sounds a lot like the shure. I think it's more balanced but definitely less bass than s4 for now. Hoping burn in will...