Like your honest opinion...everyone's ears are just not the same...By the way, I am currently enjoying the X3 but definitely have had the same Subaru experience...they certainly have the worst stereos...probably resulting in early onset of Tinnitus.

I'm with you on the Subaru stereo.  My parents' 2013 Outback has very loose sounding bass.

Very honest and unbiased!
Although, would have been better if you had some other DAPs (or even DAC/Amps) for comparisons...at least in terms of SQ

Any comparison with the X3? I think a lot of people will be migrating that, liking the general warmish signiture but hoping for more refinement.

In a sea of praise, criticism, especially when well reasoned and supported like it is here, is invaluable. Thank you for taking the time and effort to put this together.

I generally don't like to put comparisons in my reviews because not everyone knows what they sound like.
@BadBoySimran
I have a Sansa Clip Zip, iPod 5th generation, and iPhone 4S. By themselves, I think the X5 has the best instrument separation, detail retrieval, and soundstage depth, but the others have a more natural-sounding soundstage and I feel surrounded by the instruments on the stage as opposed to just listening to them half-way in a concert hall. In terms of sound signature, I would say the others are more in-line to what I would call neutral or uncoloured.

In terms of DACs and amps, I have the Objective DAC, JDS Labs C5D, Objective 2, JDS Labs C5, and FiiO E12 at hand. I think the ODAC/O2 combo sound the most transparent to me and the sound signatures are quite different from the more coloured-sounding X5. I had similar observations with the C5D but it's a tad bit warmer and closed-in sounding compared to the ODAC/O2 combo. Using the line-out feature of the X5 (and using only portable amps), I think the C5D and C5 retain having a more transparent and spacious sound but don't quite have the instrument separation of the standalone X5. The E12, as with the rest of my amps, remove the fatiguing sound that I was encountering with the X5, but the E12 is still a bright-sounding amp with a narrow soundstage and not very good instrument separation to me, so it wasn't a good pairing with the X5 and might be worse than the stock X5 amp in those regards.

@Stuff Jones
I only briefly heard the X3 and I would say that the X5 is an overall improvement in sound, if you completely ignore my observations of the X5's fatiguing sound and don't mind the hallway-like soundstage. The X3 sounded a little more balanced to me in sound on the other hand (having a sound signature more in-line to what I would call neutral like my other DACs/amps/portable media players). I also greatly preferred the user interface of the X3 since I encountered no hiccups or navigational errors.

Great review! The other reviews (to me) is too fanboyish, so it's nice to finally read a neutral review.
I made the mistake of buying the X3 over the DX50 because of those fanboy reviews and the X5 reviews is a mirror image of the X3 reviews, praising and magnifying everything good and barely mentioning any of the problems, bugs, etc. 
For now I'm scratching the X5 off my list, because just like the X3/DX50, the DX90 look like it'll be the better option.

Great review, mate

Appreciate the mentioning of the flaws. 

I do was disappointed BIG time by the sound stage, although the line out of my Demo Unit into my PB2 was rather neutral imo, it's got more color than the NFB ES2 [but what doesn't] 
 
still that sound stage... big eww for me as well. I tried not to flog it in my blog but... the poor X5 is getting a direct comparison paragraph in my head fi review, of which I'm typing now :3

This is the only really serious and honest review of the X5. It was obvious that it wasn't going to be as perfect as they do see here, especially in their colored sound

This review exactly mirror my time with the demo unit of X5. I would have spent my money on this if not for that sound stage issue and vibrant sound. Classical music don't fit good with X5.