Have been listening to my new iCAN Micro for couple weeks now. Before that I use the headphone output directly out of my iDSD Micro.
First of all i just want to say that iDSD Micro is great. One of the best gears i have ever bought. I buy and sell headphone gears pretty often just to try different things. that's what this hobby is all about, right? iDSD Micro is one thing i think i will never let go. It is just so flexible and good looking. Not to mention that it sounds great. I don't know how iFi guys were able to pack so many great features in such a small and beautiful package and sell it for a very reasonable price. Btw, they weren't joking about using iDSD Micro to drive the mighty HE-6. I tried and it sounds pretty good for such a small device.
Going back to the iCAN Micro. A lot of people will ask why one would even need the iCAN if you have already got iDSD Micro which has a very capable headphone output. After adding the iCAN Micro after iDSD Micro the sound becomes sweeter and warmer. The only complaint i had with iDSD Micro before is that it could sound a bit dry from time to time, and looks like iCAN is the perfect cure for that. I think it might have something to do with its Class A circuit. I am a Class A guy. My main stereo has a set of Pass Labs XA60.5 Class A mono amps, and i also use First Watt J2 Class A amp for my desktop system. To me a class A amp (well designed of course) just sounds more musical and more effortless. It brings you closer to the music. iCAN did exactly that. I also enjoyed the 3D and Xbass feature. For 90% of the time i listen at Xbass Mid setting and 3D Max setting. I really like iFi's implementations with both as their effects are subtle.
I am currently using this set as my office setup. I am completely satisfied and have no intention to make any change, nor do i think that i can do any better without spending significantly more money. I highly recommend this combo to anyone who is looking for a good and flexible desktop setup as well as with some portability. (i just took this set to London for a business trip and they worked beautifully. They didn't take much space in the bag and you can use iDSD Micro on the plane. :-))
oh, forgot to mention that i use this set to drive my Yuin OK1 earbuds as well as Hifiman HE-560. Both were driven beautifully by this combo.