I should have linked you to my BSW install... or rather reinstall, as I was less than impressed with BSW's method of recommended installation.
As to your thoughts on the sound, about what I had anticipated. It fills in some areas, falls short in others, and is definitely not worth $500. I'm glad mine came "gratis" with the X5. A very pleasant surprise because the way the PO had it tuned you couldn't even tell the thing was in the truck. Sounded like garbage. Some fiddling around (I've gotten decent at tuning by ear) and it performs well enough for something that doesn't take up any space.
BTW, it will sound better if you install a grille in front of it on the panel. Like this:
Edit: BTW what was your mounting solution for the amp? Zip tied as BSW shows in their videos? *bites nails*
Here's what I came up with after some noodling about with some ideas:
This makes adjustments very easy and convenient... though admittedly once it's set properly you shouldn't really have to mess with it again. I've been known to use nail polish or other means to lock gains/xover settings on customer installs after tuning and getting "auditory approval" from a customer when installing systems. Prevents someone getting all hamfisted with them and blowing speakers or amps.