Couple of thoughts:

It sounds like you're using the right materials on the panels. I also reread your first post and it does sound like you've done your research concerning placement of the panels. I still think it's possible that you're not soaking up enough of the bass frequencies with the panels. Here's a website you've probably seen:

www.realtraps.com

Ethan has some good articles about controlling bass.

The "Hypertweeter" works all the time, not just on DVD-A and SACD discs. It's just that most CDs are bandlimited to about 20khz, or the natural range of human hearing. DVD-A and SACD aren't limited in this way. According to KEF, the "Hypertweeter" kicks in at 15khz so normal material does make use of it.

I'm not quite sure how you would test the tweeters, especially with a coaxial arrangement. My point was that if you feel like the speakers not performing properly, take it back now instead of later.

As for expectations of sound, you know what sounds good to you. Don't compromise. It may be that the speakers aren't a good match for your electronics and/or room. I would give them a little bit more time but don't wait too long. If they're not right, they're not right.