Help buying a portable headphone amp!

The iBasso D10 maybe?
I have heard it with the HD650 and did find it to do quite a nice job. Not the most powerful amplifier, but then again that is where most portable amplifiers fall short in comparison to desktop units.

Check it out.

ibasso D4 (dual dacs) sounds great for $219 + shipping. To my ears it sounds better than the D10 in the clarity department and it's cheaper. The only thing is it takes a 9V and the battery life isn't particularly good. But it really is a nice amp/dac for the price and sounds great as a stand alone dac, stand alone amp, or both.

ibasso d10 and d4 which were recommended above are getting lots of praises.
i've never had any experience with them but i had ibasso d3 python a while ago.
i loved the sound (driving big cans like hd600, hd650, dt990) but sold it because it was too big for my setup.
it is powered by 5 aaa batteries. i've seen it sell for way under $200 on sell/buy forums here. i do not know whether it is bigger/smaller than d4 and d10.
it was such a great amp. if i had an ipod, i'd definitely go with d3 python but i have a cowon d2 and have to go with something smaller.