Tvhead.
You're right. This is what I wrote about the HP550 back then. It was based on a brief audition in an electronic store in Stockholm. The phones were on a stand together with other phones fed from a cheap boombox system. I must admit I overlooked this. It must have been the source, which rolled-off the treble. It was not surprising since (as I wrotre then and still stand behind) several Philips buds and full size phones have rolled-off treble. With my sources and the HP550 however, I don't feel this at all. I don't think it is a change in opinion, just the pair I've been auditioning didn't sound that sparkiling in the treble as the pair I got a couple of days ago. Could be that the demo model was a deffective one also, dunno.
Still, I feel bad about it, since I've been trying to audition many phones and do it OBJECTIVELY. Obviously I failed at least once, sorry.
However, now that I have them, I've had the oportunity to hear them from many different sources and my opinion from this review stands, i.e. these are good.