The XB500's were a popular "budget Basshead headphone",but were discontinued (the xb300,500,and 700) along with price gouging.
Thus is the life of purchasing endangered headphones.
I don't think the new series is as good,though i could be wrong.
Have you heard of the "creative aurvana live!"? (not series 2,series 1)
my only concern would be durability,if your going to be carrying these around.
someone else might be able to comment on that.