Marc_0 + Club M == Great Trance
Last time the place was quite nice. People pouring in only later in the night, but great music all through.
The club itself is relatively small, but the people are interesting nonetheless ;)
For the previous Hero event, both marc_0 and the other DJs did a great job.. if this time is anything like last time, then it would be a good idea to check out Club M.
Just keep in mind that the entrance is quite low key. Follow the map and get to the green building. The entrance is from brick & mortar stair going down to the B1 floor.