I'm giving them serious consideration. The er-6 should nearly match the ER4S without the need for an amp. If I buy the ER4S or B then I also need an amp, which is a bit of an investment. I'm sure I'll get around to it at some point.
I'm more looking forward to the GR08 and ASG2, but in the mean time I picked up an RE0 for $50 during the clearance sale.