I just listened to Shpongle's latest album on my k701s, from the headphone amp on a lavry da10. I cannot imagine a better set of cans. I think Shpongle counts as trance

I listen to plenty of trance, dance, electronic music on this setup. I also listen to the same music through Beyer dt770s, which have a lot more bass than the AKGs. I use the dt770s at work where I don't want an open can, but I'd much prefer the AKGs.
The bass is not excessive, but it's not lacking. It's tight, quick, realistic (when listening to live or instrumental music, that is. what's "realistic" mean when listening to synth?). Where the AKGs really shine is detail, separation, headspace, and accuracy. On a well recorded trance album, headspace and separation really improve the music (for me). At the same time, the AKGs will instantly reveal any sloppy sound engineering (which is exactly what you need in the studio, but kind of a bummer as a listener).
I get the impression that few people listen to trance/dance on these cans, but for me, they're the go-to can for pretty much any genre. If I want tonsil-rattling bass, I'll listen on studio monitors or on my crummy stock car speakers.
Unfortunately for comparisons, I haven't listened to the other cans you've listed. Also, all my impressions are based on amped listening. I don't think I've ever dared to listen to them without an amp.
EDIT: as to trying before buying, I bought the k701s without trying them first, but I bought them from a very reputable and respected US dealer who would have taken them back if I didn't like them. You should be able to find a dealer like that in the EU, or just take a trip to the AKG office in Vienna
