I've been having a difficult time deciding which pair of headphones to keep. The X2 has impactful bass, but it is obviously behind the other two in terms of mids, clarity, accuracy, and soundstage. The HD650 is more like the middle ground here, leaving T1 as the detail/soundstage king. This is not a violation of rule #1 since I already purchased all of them. Being as unbiased as possible, please take your pick. Assume the DAC/amp paired with your choice is clean, neutral sounding.