Nice to see another Swede around these boards!
(Japp, jag är också svensk - tar dock resten på engelska för att inte vara oartig mot resten av folket här.)
I had pretty much the same question as you a week ago or something like that, though I was choosing between the SE210, Super.FI3, and the D-Jays. I was recommended to check out the Denon AH-C551, which I did (at "Hi-Fi klubben", seems to be pretty much the only place in Sweden that carries Denon headphones). I was really impressed by the sound, and bought them on that same visit. I also tried out the AH-C351, but those didn't impress me nearly as much.
I'm really happy with my purchase, they really sound awesome. Easily the best IEMs/canalphones I've ever heard (but then I have never heard any really expensive ones). Very clear sound, with a bass response I didn't know was possible with phones like these (good bass response something I've read several times that both the SE210 and the Super.FI3 lack). Very nice for progressive rock/metal (which is what I mainly listen to as well).
The build quality is also highly impressive. The housing is made out of aluminium, which gives them a very solid and high-quality feel. They don't feel cheap and plastic (well, they're not) in any way. And even though they are made out of metal, they are very light-weight.
The only negative thing about them is that the noise isolation isn't quite what you'd get with something like the SE210s. They do isolate quite a bit, but when my music isn't playing I can hear most of what's going on around me. Once I play something though, and that wonderful bass starts pounding away, the outside world more or less goes away. I can still hear engine noise or the sound of the rails when I'm on the tram (spårvagn), but I don't think even true IEMs can block that completely.
So, if you live in a city which has a "Hi-Fi klubben" (I live in Gothenburg, so I have two of them closeby), go check them out (they're 898kr, by the way)! I can guarantee you won't be disappointed with the sound (as long as you use the right sized silicon tips), so the thing to consider is if complete (or as close as you can get) isolation is really important for you.
