Just thought I would chime in here. It's been forever since I'd looked at head-fi.
I found out about this amp on here yesterday, and just ordered one of the two that went up on eBay, and separately a Cardas mini-mini interconnect to go along with it.
My setup used to be a Panasonic portable CDP > Headroom Airhead > Sennheiser HD580, and I realised after a while that the amp just could not do the headphones justice. Since then I kinda dropped out of the race for better equipment due to lack of money. My current setup is a 4G iPod and Koss PortaPro headphones -- which I've considered good enough without doing a lot of research and spending lots of money.
The amp ought to do well with the PortaPros, and I figure this is a good chance to pull out the HD580s again, perhaps this setup will suit them a little better. Thought I'm a little concerned, based on comments here, that it may still be a bit lacking considering the HD580s are 300 ohms...