No problems. The D2k are remarkably good for most music.
As for the tips I'm a bit torn on the Hifimans tips (double flanged, medium sized) vs the Senns tips (double flanged, medium sized). They both give me a good seal, but it seems as if the Senns tips gives me a little harder treble and a punchier bass and the Hifimans give me a little mellower sound as in more laidback and a little slower/boomier bass response. While I actually do prefer the sound of the Senns tips, they tend to crawl out a bit. They are more comfortable too, but the Hifimans tips stay put a bit longer. It becomes a question of preferred sound qualities and comfort versus reliability. Normally, I'd go for the comfort and sound quality, but when I'm on the go, the last thing I'd want to do is to have to push them back in at times. Don't take me wrong, the Senns do stay put for a while and the Hifimans tend to crawl a bit too, so it's not like one is really superior to the other - but even the slightest differences are noticable. But they both provide good seal and good fit. It's just a matter of deciding which to use. Plus, one big difference is that the Hifimans double flanged tips give a much deeper fit due to being about twice the size in terms of length.
The fun thing is that I'm actually sitting here home trying to A/B them as we speak. I should start programming soon instead. I have a few games and applications (Java and C# with XNA) to develop, but listening to tips is a fun procrastination.
Edit: after A/B:ing them for a bit more, I'm actually going for the Hifimans tips. The sonic differences aren't really that big and they provide a more secure fit.