Went to Sevenoaks in Reading to listen to the Rel q150 sub, here are my thoughts: It goes deep, surprisingly so especially for such a small box and I may get it largely for that reason alone. However I don't know if it was because it was being used with small satelite speakers or its position (firing into the side of the sofa i was sitting on) but I didn't think it integrated very well it seemed to be either there or not rather than seamlessly blending in. It didn't seem particularly fast when in 'Depth' mode and you could sort of feel the driver moving in and out by the sound - like a deep machine gun, in slam mode this disappeared and the sound was smoother. I've come home and played the sames scenes on my Kef 20B after taking someones advice and increasing the output from the amp, and to be honest the 20B is definately not as deep but it is fast with no boomyness although it can't fill the room as well. To be honest though, if the Kef went deeper it would be a better sound to my ears. All in all though if I can get away with it (need to do a sound check with the neighbours) I may get it for the depth alone. After reading all the comments on the Rel I realise it isn't the favorite - but i want something small.