I just got this amp and have been out of the head-fi scene for a year or so.  I modded the HD555 and ever since I really enjoyed modding and listening to different headphones.  I had the AD700, HD555, RE-ZERO, TL-02, and a cheap Sennheiser model.  The RE-ZERO's had to be my favorite because of their amazing clarity.  The AD700 were very nice for gaming and comfortable.  But now I have this amp and I have to say it does a great job with the cheap set of im-590's I am listening to it now with.  The clarity is near RE-ZERO as Joker has said, and the bass is excellent.  It's a great IEM.  But, I was looking for something that would do even better with an amp for gaming and movie watching.  I listen to music, but I mainly want a full size that will be great for movies.  Comfort is a big plus as well.  I ordered the HFI-780's because they looked nice and I always wanted an Ultrasone set.  But they got backordered or something so I need another set.  I was thinking of getting the RE-0 because i heard they do good with an amp.  They also have the clarity I am looking for.  The only bad thing is they are IEM and watching movies or gaming for long sessions they tend to hurt the inside of my ears pretty bad.  So I was looking for a full size set that would go good with the amp that has great clarity and good enough bass to shake a little during explosions in gaming/movies.  The IM-590 do a great job, but if these IEM do this good of a job, I can't imagine what a set 3 times their price can do.  Please help!

The 780's will do fine, what would your budget be for another pair? Maybe sell the others...?

after looking I am going to get the KNS8400's.  they seem to be exactly what i've been looking for in a headphone for a long time.  the 780's sound nice, but i think the clamp would make me want to destroy them in a few hours because i have a big head and comfort is a necessity for me.