After testing out the tour unit I wound up getting the new Metal MX500 shells for DS. I really love the feel of them - they are quite heavy, likely a little bit heavier than the VE Sun Copper buds. It gives them a more premium feel that was missing from the plastic shells. Overall sound is quite similar to the tour unit, but perhaps feels a bit wider with a blacker background. I haven't A/B'd them much, but they feel wider than my Serratus, and definitely a "deeper" background. Still not quite as enveloping as SC, but the gap is not very large.
I did notice two things stand out to me more - a sharpish peak around 5.6KHz, and very forward details thanks to a boost in the 10-12KHz region. Unfortunately those combined makes the stock treble a bit less refined than I would hope for a TOTL bud. One of my test tracks is Graveyard (Acoustic) by Halsey, and I found it a bit fatiguing at higher volumes. The forward details will really lay bare any poorly mastered music. For example, in Something Human by Muse, the almost low-fi recordings of Matt Bellamy's vocals really comes across with DS, moreso than anything I've listened to before. On the other hand, those details plus the tuning makes some music really stand out in an amazing way - listening to the Les Miserables 10th Anniversary album is stunning, and incredibly lifelike. (That performance on that album was what convinced me to buy DS after demoing it.) These issues are less noticeable at lower volume, but still present.
I'm not sure if these characteristics are specific to my unit or not. The user after me graphed the tour unit and also noticed these issues (sharp 5KHz peak, high peak around 10-12KHz).
I'm a big EQ user, and using that graph and a sine sweep I made the following EQ. With this EQ I find it smooths out those rough edges, and tames down some of the midbass that can border on overwhelming the rest of the range:
With that EQ, in my opinion DS really achieves its peak performance - an incredibly lifelike, reference tuning. Acoustic guitars and pianos really stand out for their timbre and sensation. Both male and female vocals feel uncolored, clean, and natural. At this point, this is my top bud, even above Sun Copper, thanks to its beautiful tonality, soundstage, and build quality. It is, however, quite pricey, and ideally wouldn't require extra EQ to bring out its full potential.