Originally Posted by NZtechfreak
Sorry, I did see your question but I didn't have time to answer it right away and promptly forgot about it :(
In terms of sound they are all great. My personal preference as far as that goes from most to least favoured is Pico-->Apex-->Intruder, I find the Pico and Apex quite forward which is good for my listening habits on the go and I think the Pico is just slightly warmer. Having said that there isn't a great deal in it in all honesty.
In terms of other pros and cons: the Apex has the best form factor for use with slab-style touchscreen phones being slim, it also has the ability to bypass USB charging when connected to the host device (which is a major bonus when you're running it from a phone), overall with these in mind I would rate it the best for using with Android phones. Worth bearing in mind that it does not work with the Galaxy S4, although every other Android capable of USB audio seems fine with it. Obviously the Intruder being fully balanced may be a relevant pro in its favour if you need that, but if you don't need fully balanced output I don't think it is worth the extra expense compared to the other two. Fit and finish for all three is beyond reproach really.
Thanks a lot for getting back to me about that, techfreak. You really helped me out. In the end I took a shot at the new iBasso D42 dac/amp after reading your little review and comparing with some others around. The crunch is on, so I really had to pull the trigger or I wouldn't have been able to have anything shipped before I move.
The D42 has dual WM8470 DAC chips, 230mW->32ohm output, doesn't need USB-ARP with my GS3, does 24/96, comes in cheaper than all the rest, and has a solid build quality. I absolutely would like to have the form factor of either the Apex Glacier or the V-Moda Vamp Verza, but I'm going to test the waters with this first and see how I take to the scene. The price tag on those other two is too high for a portable rig for me, I'd rather put it into my home setup after I move. The D42 also has rollable op-amps, so that's another plus side and something I'll get to test out.