Descent is by far the "best" sub I've ever owned!!
I have been enjoying my Descent sub for a year now and it continues to amaze me at just how powerful, accurate, and deep this sub is capable of. This is without a doubt the best sub I've owned and listened to. Yes, like Joe said, it's going to take a while to really show off it's full potential. It's new so it needs to loosen up, and as the months go by you will notice the bass sounding fuller and deeper. It sounds like you're getting it dialed in to where it's sounding really good, too cool!
I have found that it blends very well with my reQuests. At the very beginning when I first got the sub it took a while to get everything just right. But once I did, boy did (does) this thing make a world of difference to the sound. It went from sounding really good to really awesome! Like both of you, I also had a ground loop hum problem with the Descent. The hum, like Joe's, was also caused by my cable TV (which I no longer use). After I disconnected the CATV voila! no more hum. I have my descent connected using a balanced XLR cable and it is 100% hum free.
For my own curiousity I temporarily swapped out the XLR cable for an RCA type interconnect and found that a slight amount of hum was once again audible, but this time only from approx 1-2 feet away (and not audible at all from my listening spot). After I re-connected the XLR the hum went away completely. I just wanted to see if it made a difference in sound using a balanced cable over an RCA, and in my case it did. Just thought I'd share my findings. Hope this helps.
And BTW congratulations on your new sub!
The more you use it the more you're going to love it!
Enjoy!
SV