Well, if you're using integrated mobo sound as your mean, then I'd agree that the Fiio line is an improvement over what most people hear. Based on my experience with the better ($100-200) consumer PCI sound cards, it's more of a toss-up once you're in that range.
I'm not ridiculing the device, but when I think audiophile category (in my personal taxonomy), the Fiio E7 and similarly performing devices are one or two standard deviations away from the boundary.
The great thing about DACs is that the price-performance ratio has become significantly skewed in favor of the customer. In my ears, and some of my friends, the gamma2 outperformed retail external DACs close to the $1000 category. The $750-2000 has amazing bang-for-buck performance these days, and that's not getting into DIY models like the Buffalo, which I recently heard and was pretty impressed by its musicality.
I agree that the differences are easier heard on speakers in most cases, but I've found the higher-end Staxes to be pretty honest about the quality of specific components.
Headphone amps are those funny things, where, based on what I've heard, the first tier levels out around $900, then it's relatively flat until you get into Balancing Act territory. I've heard a bunch of headphone amps in the $900-1500 range, and none of them stood out to me (in a positive or negative way). I'd love to hear the Dark Star and Liquid Fire, more expensive headphone amps people rave about, to see if they are significantly better than the mid-range I've heard. Other people may disagree, but I've heard definite tiers carved out. Ofc, transport, tubes, software, etc., also all make a difference.
Edited by Elysian - 11/4/11 at 6:23pm