I really started digging the squished pads with the HD58X. For me, it gives an extra advantage of bass “always being there” for low listening volumes (~70dB or lower).
Allow me to quote myself a joke I made this week in the HD660S thread:
The more I listen to these HD6-family Senns, the more I’m convinced my ears should be literally touching the drivers. Yep, it means I’m a mid-range whore – the hard way, of course. 
HD58X is a keeper for me.
Cheers. 