I had the combination for awhile and it's good enough. The HeadFive is a little warm, so it's a good match for the DT880. However, when I got a tube amp, the HeadFive went into storage and then was sold to fund the Zana.
What are you planning to use as a source? One thing about the HeadFive is that the gain isn't set particularly high. Now, that is a good thing depending on perspective. It keeps distortion down and the HeadFive is a nice, clean amp. The drawback is that it didn't do much with an iPod driving it. The HeadFive only perked up when I used it with a standalone desktop-style CD player. CD players (and other gear) that plug into the wall don't worry about conserving battery life, so they give you a decent amount of output power. If you plan to use the HeadFive with desktop components, it'll do fine.