At the outset, Manu please do not open multiple threads for the same topic.
Manu, I have mentioned this to you before, but you are very clearly going the wrong way. You have been looking at changing subs and amplifiers at regular intervals. Though there is no harm is this, I have never been able to understand what you find missing in your current system. Irrespective of how much money you have to spare, changing system like changing clothes is not a good idea. I can understand changing equipment for a steep difference in technology such as TrueHD, HD audio etc, that old equipment cannot handle, but not for the reasons you have been mentioning.
Setting up a really good AV system involves a number of things. One of the most important is room acoustics. If you get professional help and set up your HT room properly, even your current system will sound completely different, and, hopefully much better. A little bit of work on reflection points, control of standing waves and level matching will help you hear sound with pinpoint accuracy, even at low volumes. Believe me, stuffing cotton into covers and sticking them on the doors and walls will only work for a small percentage in controlling acoustics.
As I have suggested before, I would suggest you get a professional sound engineer to measure your room and suggest what needs to be done. He will also recommend some equipment, if needed. Based on those recommendations, we can all look at what is good or what is bad. Because then we will have a base to work upon. Right now we are all, including you, just shooting in the dark. For example, for me, the Hsu is the ultimate, and I would never need to look beyond that. I have heard a number of subs, but I like the musicality and accuracy of the Hsu. BUT, I sense you are already looking for another sub or multiple subs. So, I am not able to understand your requirements at all, and to me, many times, it just seems you want to keep up with the Jones.
I could be wrong about what I am saying. But I would suggest you make a long term plan and stick to a system that will serve you for 3 or 4 years. Maybe you should even stop coming to HFV so that you do not get unnecessarily tempted.
Cheers