i just recieved the denons and the only other IEM i have to compare them to are the skullcandy's, they are both about £20 on amazon.
Here is a review of both of them, tested with lots of genres and all at 320Kbps from a Sansa Clip+.
First of all build quality, the denon's feel much nicer and are better built, with a cable that looks less likely to break than the skullcandy. The volume control on the skullcandy is ok, and quite slim so it wouldn't get in the way too much.
Acessories: the denon's came with 4 pairs of silicone sleeves, the skullcandy only 3. The denon's have a clip which you can attach to the cable to clip to your clothes and a cable holder, the skullcandy came with a little pouch to keep them in.
Comfort: the denon's are so comfy, i hardly feel them when i have them in, whereas the skullcandy is quite difficult to get a good seal and they are not very comfy.
Soundstage: both fairly average for the price, the denon wins by a bit in this area.
Instrument separation: the denon's are much more clear and easy to distinguish each instrument, the skullcandy sounds like they are all crammed together with no real separation (veiled).
Clarity: the denon's have a clearer sound than the skullcandy.
Highs: the highs on the skullcandy sound very distant and recessed, the denon's highs are slightly more forward and sound more detailed.
Mids: the skullcandy mids are fairly good but recessed and the skullcandy's can be sillibant at times, the denon's are recessed to but not as badly and they have very smooth mids.
Impact: the skullcandy wins in this section, but not by much, the denons have very nice impact too.
Extension: the denon's have much better extension, they reach very far down, whereas the skullcandy's roll of quite a bit before the denon's.
Overall bass: the denon's have more bass (which can be a bit overpowering depending on the song) but better extension, the skullcandy has more refined bass.
They are both bass heavy IEM's with the skullcandy having more controlled bass but in less quantity, the denon's have plenty of bass with very nice extension. In my opinion the denon's are better because they sound clearer, are more comfortable and suit most genres fine. The skullcandy sounds very veiled.
This is my first proper review so i'm sorry if it's not great. I hope to get better over time. Thank you for reading this.