I am sure it is a nice product and I'm considering getting one, mainly for the high storage capacity, if they can sort out the bugs.
BUT.... it is hardly a surprise that the reviews have been good and consistent. Most of the people in the review loop are excited about the product and given the impact perceptions and expectations have on sound quality, this would have to be a very poorly-designed product to get bad reviews for sound quality - and that it isnt.
Ergonomics play a HUGE role - far more than the minor-to-the-point-of-insignificance differences between the various DAPs in the market today, IMO. However, all the ergonomic issues seem to getting swept under "oh well, it will be fixed in a future firmware update". Given that this is going to be a $400 product, is the second DAP in a company product line and the past experiences with the X3 and the DX50, it doesnt exactly inspire confidence that the product *STILL* cannot read the ID3 tags consistently, or that gapless playback still doesnt exist, etc. etc. Personally, I dont care about what is GOING to happen - I care about what the product is like right now, and IMO, it is still a work-in-progress.
Please note I am not knocking the product and I am not saying that the people who have reviewed the X5 have been deliberately hiding facts. I am just pointing out that the reviews have been tending more towards the optimistic side, which is to be expected given the nature of this world tour.