i bought C3 after plenty of good reviews and was not disappointed. C3 sounds really neutral with good separation. while its not true analogue sounding it gets pretty close to this.
my portable setup works great and produces truly hifi sound with great meaty bass and separation. i fully recommend this setup to everyone who wants good bass and detail with a good soundstage and life like sounding music. i use C3 with Digizoid 2 portable subwoofer for earphones and Musical Fidelity EB50 earbuds. this combination is a killer, really have not heard anything better to date. of course do not expect C3 to beat proper hifi rack. C3 cannot deliver the sound which sonus faber floorstanders with tube amplification can deliver, but hey, i doubt any portable would be able to achieve that. for the money i find my setup unbeatable but what is more important sound quality is amazing and it really makes you want to rediscover your digital music collection.
C3 is great player when properly matched with good headphones and perhaps portable amplification. for me Digizoid and MF EB50 did the trick and put a wide smile on my face.
comparing to my trusted Cowon S9 i can say C3 delivers cleaner sound and better instrument separation and wider stage at neutral setting. S9 is good with tweaked settings but it is unable to match C3 in instrument separation and dynamics. all in all S9 is casual listener player while C3 is critical listener player. both do their job very well.