After a lot of questions on this forum I have decided Santa Clause to be early.
He just brought me a Beolab 2 to extent my B&O collection:

I always thought my Beolab 8000's where lacking of some bass in dance music, or songs with a band (like the eagles, duffy, etc.). I always missed some power/ depth in the music and hoped to get this with the beolab 2. Otherwise, for light jazz and acoustic music it was great (like katie melua or Jack Johnson), so I didn't want to ruine this with a lot of bass.
When the Beolab 2 arrived I had installed it by attaching the beolab 8000's directly to the beolab 2.
I left the soundsettings as it was with just the beolab 8000's and just gave it a try with some kinds of music.
I have to admit that it was very boomy and in the Eagles farewell tour e.g. Also tried some dance music and it was so loud I had to turn it down.
I tried to adjust the settings on the back of the sub and in the menu of the beocenter and took a couple of hours (!) to adjust a little and relisten the same song. After being satisfied with the sound go to the next song and if necesary adjust a little bit more.
After a couple of hours the sound was absolutely amazing. Testing the farewell tour of the eagles (in HD) was if I was there in the concerthall. A lot of depth in the songs, good deep bass, but never been boomy at all. Even dance music like david guetta result in a deep and even thight bass. But also listening to katie melua hasn't decreased in soundexperience. It was even improved and more bright because the lab's 8000 where releaved of the basses.
So I do understand now why some people call it boomy or slow, but I think they have never tried to set it up properly.
After taking some time to set it up, it is absolutely amazing how full the sound can be in the whole room. It's absolutely amazing for all types of music!